What is a plotter?

What is a plotter?

Plotters are printers - and "plotter" is a term applied nowadays to describe those printers which print large scale images or drawings, often CAD drawings showing building or engineering plans, POS images, or big canvas prints which are usually either A1 or A0 in size.

Technically speaking, it is an outdated word, since the technology now employed with newer machines no longer actually 'plots' the output due to changes in printer design and technological advances. In other words, the term "plotter" actually describes the original technology whereby plotter pens plotted across the paper to create drawings. Despite plotters being replaced for the most part by the mid 1990s, the term "plotter" lives on!

What applications are they used for?

Plotters have a wide variety of applications, since they are capable of printing large scale images and can be used with many different types of media. Typical uses include architectural drawings, maps, large signs or POP adverts in shops and supermarkets, art gallery prints or large photographs etc. Media options include: vinyl, canvas, fabric, card, paper, film, adhesive paper, coated paper, billboard paper etc and the media can either be sheet fed or roll fed. Common widths of media purchased are typically 24", 36", 42", 60" wide. Inks are also variable and are supplied as dye based inks, pigment based inks, and dye or pigment based UV inks (for outdoor printing, to prevent fading). 

Who makes plotters?

Various companies make plotters such as Hewlett Packard (HP), Roland, Canon and Oce. HP is the biggest manufacturer and has the largest market share both in the UK and Worldwide. We specialise in HP Plotters, better known as Designjets, because they are well built, reliable, offer excellent value for money (including providing savings in terms of cost of ownership when compared to competitors) and they get the job done! Our competitors often offer a wider range of large format printers - citing Canon as their favourite because customers need to upgrade every 3 years. A lucrative sales opportunity for the reseller - however we just want the best quality for our customers. Once you purchase a HP Designjet you'll keep it for 5-10-15 years or more. 

You may also hear the term 'large format printers' or 'wide format printers' in the industry to describe these machines. If you click on the 'HP Designjet Showroom' link above you can glimpse HP's latest Designjet models. In essence, there are technical printers (for the likes of Architects, Engineers and other CAD users) and photographic quality printers (for the likes of Graphic Artists and Photographers).

 

A little bit about HP Plotter History 1968-1990s

In 1968 HP introduced their first plotter - the 9125A flatbed plotter - designed to be used with the 9100 calculator and connected to the I/O slot at the back. This plotter famously made an appearance in the 1971 movie “The Andromeda Strain”. After the 9125A, HP continued designing new plotters based on the original 9125A design until 1977.

During this time, the only way for a business to get high resolution graphic output from computers was through pen plotters. Pen plotters provided a variation of resolution between 72 dpi and 100 dpi and line resolution equivalent to 1000 dpi. By 1977, HP started to introduce different style plotters which would carry a greater number of pens (which were capped to stop them from drying) together with improved reliabilty and roll feed capability.

At the end of the 1970s HP then introduced paper moving plotters to replace the old flatbed technology (making the printers cheaper and smaller). The HP plotters employed a technique of physically moving pens across a carriage while moving a sheet of paper back and forth under the pens. This enabled the device to draw (or plot) any shape needed by the drawing. This was a great way of producing line drawings, but not so good at creating solid blocks of colour. These plotters took a long time to produce a drawing by today’s standards, typically taking 5 minutes to produce an A4 line drawing while an A0 output could take upwards of 45 minutes. Sometimes the plotter pens could dry out mid-plot (especially pre-1977 models) which meant the whole print process had to start again.

In 1981 HP notably entered the large-format plotter business (previously the domain of companies like Calcomp and Versatec) and within 6 years commanded a market share of almost 50%. Following on from the success of the DraftPro and DraftMaster range of plotters, HP introduced the 7600 series mono Electrostatic Plotters in 1988 - providing colour models in 1990. However the Electrostatic Plotters were short-lived because in the early 1990's they introduced the Designjets that you see today.

The introduction of HP Designjets

Following the introduction of HP Designjets, the Electrostatic Plotter market collapsed very quickly because the Designjets combined lower capital + lower operating costs.

These devices used a technique for dropping tiny ink droplets onto the paper. This meant that the paper only needed to make a single pass through the machine while the print heads moved side to side dispensing ink, massively improving performance and reducing output times to seconds rather than minutes.

This new technique was much better at creating solid blocks of colour and didn’t suffer from pens drying out midway through a drawing, but initially the ability to create solid continuous lines was not as good as that of the older style plotters. As with all things, time brought progress.

The Designjets have now moved up from 4-6 colours up to 11 colours (plus gloss enhancer) for the photographic range of Z series Designjet printers. Printing ranges from 24”-60” wide rolls with some machines capable of alternating 2 (or more!) different sized rolls of paper and/or handling upto 91.4m length rolls.

Historical HP Plotter Models (all key information obtained from www.hpmuseum.net)

• 9125A flatbed plotter - HP's first flatbed plotter – designed to work with the 9100 calculator using electrostatic paper hold-down, which plotted 10”x15”. (1968)

• 72xx series flatbed plotter – 1 pen plotter – worked with most computer terminals and plotted 10”x15”. (1971/1972)

• 9862 flatbed plotter – Mechanically almost identical to 72xx series plotters, and designed for connection to HPs 98x0 computers (1972)

• 9872 flatbed plotter - HP’s first multi pen plotter which replaced the 9862. The first 9872 had 4 pens which were capped to prevent the pens from drying out. The 9872s added automatic rollfeed capability and the 9872C carried 8 pens (1977).

• 7221 flatbed plotter - 1 pen plotter – designed for computers that did not output HP-GL instructions - this was a version of the 9872 flatbed plotter.

• 7225 flatbed plotter – 1 pen plotter (uncapped) provided reduced costs and improved reliability with improvements in electrostatic media holding technology (1978)

• 7220 flatbed plotter – incorporating HP-GL language (1979)

• 7580 – HPs entry into the large format plotter market – code named “Bertha” this was the worlds first “grit wheel” pen plotter and combined high speed with high line quality at c50% of the price of comparable products manufactured by Versatec and Calcomp creating a storm in the marketplace (1981).

• 7470A – 2 pen plotter (using short body fibre tipped pens) which plotted on A4 size media and formed the world’s first small format paper-moving plotter – this was a replacement to the 7225A flatbed plotter and proved very reliable with higher speed. (1982)

• 7585A – This replaced the 7580 capable of printing up to A0 size by roll feed and used short body fibre tipped pens. (1982)

• 7475A - 6 pen plotter for use on A4 and A3 paper – and especially popular for Lotus 123 applications. This was a replacement to the 9872 at a fraction of the price with better performance but without the roll feed or liquid ink drafting pens (although by 1985 a special carousel was introduced allowing it to use the liquid ink pens) – and with 2 pens less than the 9872C version. This proved to be HPs most profitable single product and most popular pen plotter ever made (1983).

• 7090A – A digital plotter and HP-IB analog instrument recorder compatible with the 7475A (1984)

• 7550 - 8 pen plotter which could plot on many different types of media. Very reliable and “most advanced small plotter ever built”. This machine used both short body fibre-tipped pens and long-body roller ball and liquid ink pens, with the capability of automatically adjusting pen speed and tip force for the different types of pens. The 7550B also offered memory upgrades (1985)

• ColorPro – 8 pen plotter, plotting on A4 media and priced one third less than the 7475 model – however initially sales were far below that expected by HP although it did eventually take 50% of the volume of 7475 sales (1985)

• DraftPro – Sheet feed plotter with maximum of A1 plot size – designed as a low end large format printer. Slower than the 758x series. (1986)

• DraftMaster – Roll feed plotter with maximum of A0 plot size. Replaced 758x series plotters . HP/GL-2 language capability and faster speed added in 1990. Noted as being the “most advanced pen plotters ever made by HP”. (1987) Until 1987, HP Plotters were the only cost effective method of getting graphic output in colour from computers and despite limitations (i.e. could only draw lines and vectors, couldn’t reproduce raster or photographic images) they proved to be the colour output device of choice – with HP enjoying over a 50% worldwide market share.

• DraftPro DXL – A slightly faster version of the original DraftPro – this was later replaced by the DraftPro EXL which provided AO plot size (1988)

• 7600 Series Electrostatic Plotters – A1 & A0 size electrostatic mono printers – HP later introduced colour in 1990. (1988)

This article is brought to you by HP Plotter www.hpplotter.co.uk

HP Designjet Drivers - where to go if you can't find them on HP's website

For those of you looking for HP Drivers and Downloads you may find that HP have removed many older Designjet printer drivers from their website as the printers are no longer supported. (http://www8.hp.com/us/en/drivers.html?jumpid=reg_r1002_usen_c-001_title_r0001)

However, be assured that www.hpplotter.co.uk can still supply all drivers - both new and old - and also offer an excellent reference site for Designjet Users called World of HP.

About Printer Drivers: 

You will need to know the operating system that you are running on your computer in order to install the correct driver.  Designjet Printer drivers are different for Windows XP, Windows Vista, Windows 7, Windows 8 etc - even for the same printer.  Mac operating systems require different printer drivers as well. 

This brief article was brought to you by www.hpplotter.co.uk

How to be a winner with every Designjet service and repair!

We deal with thousands of customers who need a Designjet service or repair. Sometimes we wish we could wave our magic wand and have everyone understand our business. This would enable them to get the best results each time; their repairs would cost less and they'd get up and running more quickly. Here are some of the things that we wish we could 'magic' a better understanding of:

1. The Decisive Person "It just needs a service" 

We ask ourselves - is this a very experienced former engineer - or is it someone who's got a problem with their printer and actually needs a repair (but is just calling it a 'service'). A service is not a repair. Very few of our customers suddenly think 'I want to book a service'. It's normally a knee-jerk reaction to a printer problem that they can't resolve themselves. 

So...if you have a problem with your printer be upfront and say 'I have a problem' rather than telling us it just needs a service. Then explain what that problem is. Far from reducing your bill by calling it a 'service' what happens is that an engineer goes in with perhaps just a carriage belt (the main item that fails) but expecting no parts will need replacing. Then they are suddenly confronted with burnt out motors, error codes, broken handles, loud clunking noises etc... These are significant issues that point to a need for replacement part(s). Alas, this means that if the engineer doesn't have the parts on his van stock your printer will be out of action for longer and you'll have a revisit charge which might have been avoided!

2. The Impatient Person: "I need someone NOW!!"

We'll always do our best - but you'll find that most engineering companies also support a large number of contract customers who pay for a guaranteed response. These customers will always have priority over any customers who don't pay for this service - it's only fair afterall! If engineering companies can fit you in around their contract customers they will always try - but if they can't you will have to wait. If a printer breakdown is a catastrophe for you then we would always suggest taking out a Support Contract so that you aren't waiting at the back of the queue.

3. The Money No object Person: "I don't have time to discuss the problem - just come out please"

Not a problem - we appreciate you sometimes don't have time to talk. We can always prepare an estimate covering callout and labour and then advise you if any parts are required once our engineer has had an opportunity to assess the fault onsite. This may cost you more in the long-run, since we may need to revisit to fit the required part. You may also want to consider a Support Contract if your need is urgent.

4. The Misinformed Person:  "The printer is less than a year old and it has a problem..."

Let's stop right there. While we'd love to quote you for a repair we won't do it - because we're much too honorable. We like to remind you that HP provide a warranty on all new printers - some printers have 1 year warranty and a certain few offer 2 years warranty. If your machine is still under warranty simply phone HP and they will fix your problems under the terms of the warranty free of charge. If there is a reason why you prefer to talk to us instead of HP then of course we will help.

5. The Incredulous Person "Why do you have to revisit with a part?"

Some customers assume that since the printer model was provided at the outset, the engineer would 'naturally' be attending with all parts for that printer. Wrong! Sorry - and it's not because we're inefficient or lazy. If you can imagine: our engineers drive a typical service van and attend around 4-6 jobs per day (allowing for 1-2 hours on site per job including travelling time). If you can then picture the size of the large format printers and imagine squashing 4-6 large format printers into a standard service van, you'll understand that it's not possible to carry all parts for every printer each day (in fact they'd need several vans trailing behind them!). This is why it's important to understand the fault before we attend site, so that our engineers load their vans parts which are most likely required to repair the fault. Their aim is to get you up and running first time so that you'll come back to us the next time you have a fault. 

6. The I want it for FREE Person: "you repaired it 8 months ago, and it's broken again" 

Like many engineering companies we charge on a time + materials basis and guarantee the workmanship for a month (and all HP parts for 3 months). After this you have to pay for any additional service or repair costs.  One important thing to look out for, from your point of view, is that Designjets can last many years without any faults and then suddenly the maintenance kit items (those parts which HP know wear and tear with use) will start to break in succession. if the belt breaks one month and then another part breaks a few months later you should consider getting the full maintenance kit replaced - otherwise you may find a flurry of engineering visits occuring over a relatively short period which will cost you a significant amount in engineering labour and parts. Purchasing the maintenance kit upfront will save you several hundred pounds rather than buying the individual parts. 

 

THE 8 THINGS THAT SOME PEOPLE FORGET TO DO

(that could mean an abortive engineering visit or revisit):

1. Find out the proper Printer Model or Fault - both are necessary. The model number ensures we bring along the right parts.
2. Forget to be on-site - even after the engineer phones 'on the day' to set an ETA - a wasted call is a billable call!
3. Forget to have mains power and/or a light source in order for the engineer to carry out the repair
4. Forget that the printer needs to be accessed easily - the engineer needs the ability to work all around the printer with sufficient access
5. Forget to have ink, paper and printheads for the engineer to do test prints (we do remind you of this!)
6. Forget to mention any parking restrictions - the engineer sometimes needs to carry a number of spare parts which can be unweildy and difficult
7. Forget to mention the printer is kept at a different location or site
8. Offer the engineer a drink, show him the toilets and show him the fire point in the event of a fire

 

This article was brought to you by www.hpplotter.co.uk

How to de-install and transport your HP Designjet Printer

As an engineering company we receive many calls during the year requesting advice about how to transport HP Designjet printers. While smaller machines can be easily transported by car, the larger Designjets can either be boxed/palletised or transported by your removal company or bespoke courier.

In many cases you can follow the guidance notes below and you won't need any professional intervention - however in some instances it will be advantageous to have your equipment professionally de-installed, to avoid damage to the Designjet or surrounding areas - and to ensure the safety of your employees. In short if your printer has a spittoon which can leak,or the printer cannot easily be removed and must ideally be dismantled and later reassembled (perhaps because your lift is too small), or the plotter is too heavy for your employees to lift safely - particularly where staircases are involved - then we recommend you call us.

The key points to remember are:

• Remove any media loaded in the printer
• Fully shut down the printer
• Turn the power off and remove all cables and power cords
• If your printer has a spittoon, then get it professionally de-installed (unless you can ensure it's moved in an upright position) to avoid risk of ink spillage inside and outisde of printer
• Take care on lifting - some Designjets are exceptionally heavy machines - check your insurance
• Don't roll the Designjet wheels across concrete - the wheels will break or buckle. LIFT the printer!
• You can transport the printer on its stand. Ensure it's strapped down in an upright position to prevent from tipping.
• It's useful to retain the polystyrene end pieces (that came in the box when you first purchased your printer) to protect the Designjet ends from being damaged in transit
• You can remove your Designjet from it's stand, and then slide the printer into the back of your car (depending upon the size of the printer and vehicle for quick/easy transportation)
• Measure up BEFORE you move the printer to the new venue, to ensure it will fit through the door/in the lift etc
• If you've arranged for your IT Team to upgrade your operating systems as part of the general 'office move mayhem', first check that the printer drivers are available for the new Operating System. The number of times people update their IT systems and find themselves afterwards without a compatible printer driver is fairly high - so don't get caught out!

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How HP changed the World's perception of A0 paper

Do you recall the older Designjet models such as the Designjet 430 or 450s? - Perhaps you may remember they were offered in two sizes: 24 inch or 36 inch (A1 or A0 size). What you may not appreciate however is that following these models HP unwittingly sparked a change in World history regarding the true size of A0 paper - Yes - shocking isn't it!

You see, after building the 4xx series, HP asked their normal question of consumers: "What will make this printer perform even better for you?" The people spoke and HP listened. The consumer trend in the U.S. was to ask for more space around their print..."a bigger printer please" was the resounding reply - and HP picked up the proffered gauntlet. If America wanted bigger and better, HP would give it to them! The next generation of A0 printers then went into production - the Designjet 500 range. The printer offered a new print width - 'out' went the old 36 inch width, and 'in' came the 42 inch width - the new breed of A0 printer.

Everyone was happy. The Designjet 500 printers were the most successful printer ever sold (in fact - we still see many businesses operating them today and of course we still hold all of the spare parts in order to repair them). But a strange phenomenon occurred. The industry got so used to the Designjet 500 A0 printers, that their perception of what constituted true A0 size began to distort. A0 size now meant 42 inches - and this size stuck deep within the British psyche!

After time, HP started to analyse their paper sales but something wasn't stacking up. The UK market didn't want or need the extra inches (apparently!). UK media/paper sales showed that most companies were still buying 36 inch wide paper - in fact this wasn't only happening in the UK - it was happening Worldwide. It transpired that bigger wasn't really better - it was just a waste of paper. Most companies were using 42 inch machines with 36 inch width paper.

So HP went back to their drawing boards and redesigned the 'Next Generation' A0 Printer. The latest models that you see today - which include the HP Designjet T920 and T1500 printers are both A0 printers, and have reverted back to HP's original A0 printer width of 36 inches wide. It was a shock to the industry. People had grown up with 42 inches as a standard A0 size print and now HP were making a smaller 36 inch version. Confusion reigned. One of our customers found it especially hard to accept. We had sent him a few free rolls of A0 paper with a Designjet 510 printer - but he sounded upset. "You've sent me 36 inch wide paper"...he accused. "Not the A0 size you promised. Could I have the 'proper' A0 size paper please...you know...the 42 inch wide stuff". Well far be it for us to fail to meet our customer expectations so this was duly shipped out - but we were perplexed.

Unwittingly, HP was responsible for changing the size of A0 paper - although they've now reverted back to their original 36 inch width machine. As we reflect on this, we suddenly realise that we've all lived through a little piece of history - for a moment in time, the size of A0 in the UK (as far as consumers were concerned) wasn't the ISO standard of 33.1 inches - nor was it 36 inch machines - it was absolutely 42 inches wide!

This article was brought to you by www.hpplotter.co.uk

Comparing ink wastage on the Designjet T520 versus the Canon iPF750

When looking at the Total Cost of Ownership or Cost per Print, most manufacturers who commission an independent review of their Large Format Printer expect to see many different aspects reviewed - some of which may not be on your radar. Although you may look at the ink cartridge size and cost/ml, printers can and do vary in terms of how much ink they use to print the same image. Printers also use ink to clean their printheads - so 'ink wastage' is another factor to take into consideration when considering which printer offers best value for money. For this blog I'd like to explore the HP 711 Printhead, designed for the HP Designjet T120 and T520 printers and compare the ink wastage with a competitors product - the Canon iPF750.

Background on the Designjet T520 printheads

HP announced that the latest HP 711 printhead offered higher print quality, higher print speeds and longer printhead life. Recent advances in the Scalable Printing Technology (SPT) covering printhead design, fabrication and materials has enabled HP engineers to develop this printhead so that it lasts the natural lifetime of the Printer. While this in itself is a cost-saving (an average Canon printhead costs £320 incl VAT) this doesn't present the whole story on why these printheads reduce the cost to the customer.

Functionalities of the HP 711 Printhead 

The HP 711 Printhead is part of a module that integrates 4 colour printheads with the ink delivery systems for the 4 inks. The ink cartridges have been mounted onto the printhead carriage and scan with it across the paper. The module has Low-on-Ink (LOI) and Out-of-Ink (OOI) sensors for each ink, pressure regulators and filters. Directly measuring ink levels produces dependable LOI signals advising the user to prepare for ink cartridge replacement. The OOI signal stops printing to prevent damage to the printhead from running out of ink. Both LOI and OOI are more accurately sensed in a system without the complexity of ink tubes, ink pumps, and remote ink supplies as were used in the earlier models such as the Designjet 510.

Counteracting Print quality issues

In order to eliminate print-quality issues such as streaks or smears in printouts where the printheads have become caked with ink or contaminated with paper dust and debris, printhead cleaning is carried out which involves the printers running ink through the nozzles of the printhead. Normally this will unclog and clean the printhead from the inside-out.

Ink Usage in Printhead Cleaning

The amount of ink used in cleaning differs according to the printer model and manufacturer. Generally cleaning of printheads should only be carried out as and when necessary because there is a cost attached to it. Specific comparison data relating to ink wastage on the Designjet T520 versus the Canon iPF750 show that the Canon wastes much more ink and stats provided indicate that HP wastes up to 94% less ink after the first year of use:

Ink Wastage: HP Designjet T520 - versus - Canon iPF750

Wasted ink - installation: HP 7.0ml / Canon 47.4ml
Wasted ink - normal cleaning: HP 0.4ml / Canon 7.8ml
Wasted ink - strong cleaning: HP 3.7ml / Canon 29.1ml

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How to make ALL prints last longer (UV stabilised) in sunlight

One of the key selling points of purchasing a Designjet Z series printer is the fact that the inks are UV stabilised which stops your prints from fading for c. 200 years. So - what happens if you purchased a Designjet T series or CAD printer? How can you extend the life of your prints when you do want to hang them up on the wall for more than a few weeks to stop them from fading?

The answer? - by using swellable papers and where possible protecting the prints under glass or by lamination

  

The difference between porous and non-porous media

There are basically two types of media - porous and non-porous (as well as a hybrid of the two). The non-porous is also called swellable and it affects print permanence. Most swellable coatings are comprised of either synthetic or natural polymers which swell when they come into contact with ink. The most well known example of a swellable polymer uses a solubilized form of photographic gelatin as the binder. When wet, the gelatin undergoes a chemical reaction where it changes from a hard dry polymer to a rubbery gel state which allows the ink to pass through into it. After drying, the ink is then encapsulated within the coating - which in turn protects it from any contact with air and airborne pollutants.

However one word of warning is that these types of papers can be adversely affected with high humidity levels because with this type of polymer the gelatin can become rubbery or sticky - which could be problematic as the images can become blurry over time. This is the main reason why UV stabilised inks (used by the Designjet Z series printers) are mainly used by the pro market - although dye-based inks are definitely not out of the game and are perfect for the CAD market.  

By comparison, porous coatings are semi rigid coatings made up of millions of microscopic particles and as the ink flows through the particles and across the surface of the particles it gets exposed to air which enhances the drying time. However this means that the ink is very susceptible to air pollutants as they are in continuous contact with air and airborne pollutants and do suffer more from air fade.

Glass and Lamination protection

Another way of extending the life of your prints is to display them with protection - such as under glass or by laminating them. This is particularly important if you have used porous coatings (or quick dry media). This will protect your prints from something that HP call Air Fade. However, be warned that swellable photo papers have a humid and soft surface just after being printed so laminate can peel off easily while a porous photo paper has a dry-to-touch and rigid surface by comparison so the laminate will adhere really well.

Air Fade

Although Air Fade is not completely understood at this time, most research into this subject attributes the ozone as being a significant contributing factor. The likelihood is that in the near future there will be an industry standard showing 'Predictive air fade' displayed against all media - to show customers which products are highly susceptible to air fade versus products that are relatively unsusceptible. 

Research by Henry Wilhelm

Henry Wilhelm presented an article at the International Symposium on Photofinishing Technology entitled "How long will they last" where he compared performance of various photo prints, marking each porous media with this footnote: "Field experience has shown that, as a class of media, microporous papers used with dye-based inks can be very vulnerable to 'gas fading' when displayed unframed and/or stored exposed to the open atmosphere where even very low levels of certain air pollutants are present; to a greater or lesser degree, these papers have a pronounced sensitivity to pollutants such as ozone, and in some locations, displayed unframed prints have suffered from extremely rapid image deterioration".

  

Examples of HP non-porous (swellable) papers

HP Premium Plus Photo Paper
HP Everyday Photo Paper
HP Universal Gloss Photo paper
HP Universal Satin Photo Paper
HP Premium Gloss Photo Paper
HP Premium Satin Photo Paper

Examples of HP porous papers

HP Everyday Instant-Dry Gloss Photo Paper
HP Everyday Instant-Dry Satin Photo Paper
HP Universal Instant-Dry Gloss Photo Paper
HP Universal Instant-Dry Satin Photo Paper
HP Premium Instant-Dry Gloss Photo Paper
HP Premium Instant-Dry Satin Photo Paper
HP Professional Instant-Dry Satin Photo Paper
HP Premium High-Gloss film
HP Photo Paper
HP Photo Quality Paper, two sided 

This article is brought to you by www.hpplotter.co.uk

What does optimised DPI mean?

While reviewing a technical specification of your Designjet large format printer, you are likely to see the term 'optimised dpi' under the heading of Print resolution (e.g. 

While reviewing a technical specification of your Designjet large format printer, you are likely to see the term 'optimised dpi' under the heading of Print resolution (e.g. Up to 2400 x 1200 optimised dpi from 1200 x 1200 input dpi and Optimisation for Photo Paper selected) - but what does this actually mean in practice?

Dots per inch 
In other words the printer is layering the dots by passing over the same part of the page a number of times and putting several dots of colour (or different colours) in one place. This creates richer, sharper and more intense colours and can significantly change the quality and look of the final print. However, as with most things there can be a downside. A greater number of dots used on the wrong media will begin to saturate the paper causing damage to the final print quality, and the extra ink used will increase the cost per copy. It is important therefore to select the correct media when optimising your prints. It's useful to note at this point that the human eye will not be able to discern the difference between prints once they start to go above the level of 1200 dpi.

The term 'dpi' or dots per inch is a measurement of the number of dots printed per inch.

Optimised dpi

Optimised dpi is created when the printer simply moves the paper more slowly in one direction - so the size of the ink droplet and actual resolution of the device technically remains the same. In effect what you see is as shown below (left: magenta ink overlapping providing 2400 dots vertically while maintaining 1200 dots horizontally, right: normal ink dots when printer is not optimised). 

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How does a 4 colour CMYK printer manage to create different colours

Creation of different tones and colours

Designjet printers rely on a basic optical illusion where the ink dots can be varied by way of size, shape or space to create a variety of gradients and colour shades (see examples below, courtesy of wikipedia.org). The importance of the Designjet printhead is not to be overlooked because due to recent printhead technological advancements a new 4 colour Designjet now outperforms many of the older 6 colour Designjets in terms of colour gamuts.

However, one of the drawbacks of a 4 colour CMYK printer has always been that it's simply more difficult to produce deeper or more intense 'lighter' colours using dots - this is because the dots are spaced a greater distance apart to create the illusion of a lighter colour - and as this distance increases so the individual dots become more visible to the human eye. Hence the introduction of the two further ink colours - light Cyan and light Magenta.

  

Above left: Array of black dots to create illusion of a tonal graduation  
Above right: CMYK printer, showing how different patterns and dot sizes create the illusion of different colours

How the dots are actually created

Ink travels from the ink cartridges, and then journeys into what's called the Printheads (or a single Print head) - sometimes moving between the two via a tubes system. In short, the printhead has many nozzles or holes which are so fine that they are smaller in diameter than a human hair (70 microns). Ink is released from these nozzles and dots are created to form an image - you may recognise the use of Red Green and Blue dots on your television screen to create images. All Designjets utilise CMYK colours. Interestingly, this is the exact order that the inks are laid onto the media - first Cyan, then Magenta, next Yellow, followed by the 'Key' colour of Black - hence the term CMYK.

Final point of interest 

Interestingly, the 3 colours CMY will, when used together, produce a murky black colour. The reason the Designjet uses Black is to avoid using too much ink (to keep the cost of print down), avoid the issue of some media being oversaturated with ink and to create a black with more depth of tone. This is why you will often find your printer has used other colours even though you've only been printing in black! 

This information is brought to you by www.hpplotter.co.uk

What is a RIP?

 

A RIP (Raster Image Processor) is a great 'tried and tested' tool designed to solve your workflow problems, speed up and automate your print processes - and most importantly save you time and money. It can be used by small photographic studios, architects, engineers, GIS as well as large Print Copy Shops.

6 key areas where RIPs can help your business

 

1. A RIP ensures PostScript images are perfectly represented when printed

There are many different types of files you can work with. Some files (such as JPEGs, GIFs, BMP) are often made up of coloured pixels or dots, and are called Raster Images or Bitmap Images. This means when sending a photograph (made up of dots) to your Designjet (which prints in dots), the process is very simple and requires little 'translation' or interpretation.
  

 

However there are other file types which are more complicated - such as PostScript files which are also known as Vector files (e.g. PDF's, PCL and PS files - although PDF's can contain both Postscript and Raster images) and these DO require a lot of work. A PostScript file offers a smaller file size, but instead of dots it essentially contains a mathematical formula - often described as being a series of paths including curves and angles, which have a start and end point. This type of file allows for easy scalability of images without loss of image quality (by contrast when blowing up a Raster file, it will look blocky or pixelated).

Given this, the RIP acts as a translator between 'the mathematical formula' of the PostScript file and your printer. It achieves this by way of a small piece of computer code. If you have purchased a PostScript Designjet then essentially this will contain similar piece of computer code to ensure accurate printing of PostScript files. If you don't have either a RIP or a PostScript printer, then you have to rely on the printers own drivers to communicate between your application and your printer. In some cases the language is too complex, which means you may find your printout has either missing lines or wrong colour shades. However.. a RIP does much more than this!

2.  A RIP offers Faster Processing - a way to release the bottlenecks

This is the exciting bit as a business owner or user. Many people have bottlenecks in their business. For example, a wedding photographer might need to resize the same photo image into a thumbnail size; then resize the image again to print it onto canvas (adding a wrap around border as well); then resize it again for a 9 x 12 glossy photo print. A lot of manual work is involved!

A RIP will take away all of this manual work. It essentially allows you to set up many different workflows (a fast process which takes only 7-10 minutes per workflow) - a little like Macros used in Microsoft Excel. Imagine now the photographer clicking on an image and then ticking the box next to all the different workflows required. The RIP instantly resizes the images for the thumbnail, canvas print with border and glossy photo print - no more manual work involved!...but that's still not all. 

3. A RIP offers 'smart printing' with the ability to spool prints simultaneously - no need to wait!

So...we know that a RIP can save time and money by carrying out repetitive chores - but what about the time it takes to send a file to print? You can buy the fastest printer in the world but if you don't give it the tools to interpret your files quickly then you slow down the capabilities of your printer. Again, the RIP steps in and helps your workflow.

It achieves this by using RIP 'engines' (the more engines you purchase the greater the RIP price). An engine spools data for you - so if you buy 2 engines you can spool 2 files simultaneously - which means your printer can print each file more quickly. The number of engines you can purchase is determined by the number of cores your computer has. Assuming your computer is an 8-core machine, you can buy up to 8 'engines'. Another interesting feature is that RIPs can also nest your prints in order to save on media costs and can auto-rotate prints to reduce paper waste. If your printer is set up with Canvas media then the RIP will recognise the media in the printer and will print all of your Canvas prints first - then when you change your media, it continues to print all files still in the queue which meet that media criteria. However, that's not all!  

 

4. A RIP will also allow you to print from several printers simultaneously

With a RIP you have the ability to print simultaneously from 1, 2 or 4 printers (the number of printers chosen increases the price of the RIP). Notably, if you want to print to 4 printers simultaneously you'll need a 'beefy' PC. Most RIPs will process your entire file and then send it to the printer, providing you with consistent output with no lagging. This is because the RIP will only start to send data to the printer once it is all processed, as opposed to normal print drivers which attempt to process/buffer/print at the same time. 

 

5. Some RIPs contain a layout tool - offering you lots of useful functions to simplify your job

The layout tool has a graphical user interface (see image below of the Onyx Layout Tool). This tool can be purchased separately and allows you to manually modify your files (a little like PhotoShop). In addition to changing the size of your image, it also provides lots of other useful functions, including:

• Form borders around a canvas print using a mirroring technique, to allow you to wrap the image around the frame
• Provide cut lines on vehicle graphics automatically to the width of the media used
• Allow you to print with variable data - e.g. if you have 1000 posters with a different number on each you can list everything in Excel and then export it as a .csv file - to save you manually editing each image
• Tiling - to create 1 image across a wall e.g. for wallpaper

6. RIPs offer adjustability

With a RIP you can make several adjustments such as:

• If you have 2 or more printers, you can calibrate and profile each printer so you can achieve accurate and consistent colours between all connected printers (linearisation/calibration of the tonal range). This is useful where you want to use several printers to split up a single job. By carrying out this adjustment you can achieve accurate and consistent colours between all your connected printers
• You can create your own ICC profiles
• You can adjust the ink capacity (maximum amount of ink a media can hold without pooling)
• You can restrict the printheads with the amount of ink released from each

Do you need a RIP?

You should consider a RIP if one or more of the following statements are true:

• You have more than 1 person running your printers
• You need to maximise your media usage and cut back on wastage
• You need to colour match prints
• You want to increase your print productivity
• You have multiple printers
• You want to simplify your workflow and reduce time spent doing the same processes over and over again
• You would like to start creating your own ICC profiles

What do you get when you buy a RIP?

When purchasing an Onyx RIP you will receive (1) a USB stick with the software program (2) driver files and (3) a blue security key (also known as a dongle). You will then be sent an email. You have to insert your security key into your PC and then click on the email link - which in turn will run a small 2Mb file. Once you run the file you can install your software and drivers. It's really quite simple!  The only thing to remember is this: if you lose the dongle you've lost your RIP - and the dongle has to remain connected to your computer in order to run the RIP. If you decide to upgrade your RIP at any time in the future, then you will usually be sent another email link to click on, which will update your dongle. Unscrupulous dealers on Ebay have sold RIP software but not provided the security key - which makes it worthless and unusable.

The Best RIP's

The Jaws RIP offers a truly exceptional performance. This is a well-respected product with a strong market share used by over 5 million businesses worldwide (including many of the famous UK High Street Print Service Providers). Indeed, most businesses will find that the Jaws RIP consistently delivers time and time again, offering an excellent return on investment. However, for those few who need extreme performance, then the Adobe RIP is classed as the crème de la crème of the RIP World. The Adobe RIP contains the same colour engine that you see in your Adobe suite of software, offering additional peace of mind which is reflective in its price. Choosing the right RIP ultimately depends upon your business applications and processes - and there are many other RIPs specifically geared for a particular market sector which might also prove beneficial to your business. 

Our RIP Recommendation 

We recommend Onyx as our Preferred RIP provider. They offer a choice of either Adobe or JAWS RIPs and we believe they offer outstanding customer service and support. Onyx offer several RIP choices as follows:

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