Digital Print booklet:
Introduction
Digital printing is a much more modern printing method, and is produced by sending an image directly to a printer as a digital file, for example a JPEG or PDF file. For graphics based media, they are more likely to be an Illustrator or an InDesign file. None of the digital print process is manual.
An image or text is printed and produced much more quickly and efficiently than other print processes as the user does not need to create a plate. However the quality of digital prints is lower than that of other print methods as digital printers are designed to work quickly and reduce cost of printing.
While digital printing has a higher cost per printed page, than more traditional printing methods, it avoids the cost incurred in the technical processes involved in the traditional methods.
There are several different aspects to digital print, all of which can be subdivided into two separate categories; impact and non-impact printers. Impact printers involve printing machinery that touches the paper when creating the image, and non-impact printers don’t.
This guide will focus of the most used non-impact printers, and those which are in the college. This book will take you through which method is most appropriate for desired format.
Inkjet:
Inkjet printers are designed to place small drops of ink onto the paper in a certain formation that creates the desired image. You can tell what images have been produced by an inkjet printer because you can identify that the dots are very small and positioned very precisely to appear particularly dense.
There are a number of advantages associated with using an inkjet printer. They print fine and smooth details in high resolution, and photographic quality inkjet printers are widely available. On top of this inkjet printers are quieter than any other print method.
Cartridges for inkjet printers come in various combinations depending on the model and manufacturer of the printer. Some examples are with separate black (key) and colour cartridges, with black and colour combined in one cartridge, and occasionally with C, M, Y and K all as separate cartridges.
Inkjet printing can produce printed documents fairly quickly, but after they’re created you are required to wait for the ink to dry to avoid smudging, which causes a delay to an otherwise fast delivery process. However, this can be compromised due to the printers very short start-up time in comparison to other digital printers.
Laser printing:
Laser printing is another example of a non-impact printing method and uses photocopier technology. It involves a laser beam ‘drawing’ the image sent to the printer onto the stock. However, colour laser printers can be up to ten times more expensive than monochrome laser printers.
Laser printing differs from inkjet in a variety of ways:
The toner/ink in a laser printer is dry, whereas the ink used for inkjet is wet.
In the long run, inkjet printers are more expensive to operate because they require new ink cartridges more frequently.
Ink from an inkjet printer will smear but laser will not.
If the volume of what you’re printing is high, a laser printer is more appropriate than inkjet.
Personal laser printers have a high print capacity and speed,and are ideal for printing up to 200 pages per week. However, they work at a speed of printing 8 pages per minute. A workgroup printer (like the ones in the studios) are more expensive but print an average of 1000 pages per week, and print up to 24 pages per minute.
Most modern laser printers have a standard resolution of 600 dpi, which is a sufficient resolution for normal everyday printing needs. A lower resolution can cause jagged lines to form at the edge of printed images.
Laser printers can print onto transparent stocks, adhesive stocks, and lightweight card and printers with duplex printing can print double sided, by turning the page over in the printer once one side is printed. The majority of laser printers have a manual duplex option, in which you will need to reinsert the paper for it to be printed on the other side.
Solid Ink
Solid-ink printers melt solid ink to apply them to the stock, which then hardens in the place of the image. This process ensures the colours are vivid and so results in a very high quality print. This effect even transfers well onto lower quality stocks, due to the glossy nature of the finish.
These printers are constructed to make allowances for the inks constantly being melted and then solidifying again, and in it’s construction the sticks of ink don’t lose their quality or dry out when repeating this process.
Prints made using a solid-ink printer don’t smudge as the ink hardens before the print is completed. This process allows for good quality results on stocks with varied consistency and thickness, whereas the results of laser printing are much more sensitive to changes in stock.
A downside to this method of printing is that the printer may take longer than usual to print the first page, as it has to warm up, but once the printer has warmed up after the first page, the rest are produced at a high speed.
Pages printed with a solid-ink printer are not advised to be laminated, or have any finishing process involving heat applied to them, as the ink by nature will melt and distort the image. There is usually a fan within the printer that allows for the applied inks to cool down quickly.
Considerations:
Convert RGB to CMYK after you have finished your design. CMYK has a lot less colour information, so working in RGB then converting it, will allow the program to find the closest colour in CMYK. This will make the colours as close to the original as possible rather than trying to find them in CMYK.
Always test your fonts. Some fonts downloaded from the internet contain restrictions for PDF and printed format. To avoid abnormalities when printing embed the font in an Indesign document.
Avoid large portions of solid colour. Lithographic presses have the ability to create solid, even colour, toner based printers can show unevenness, as the consistency depends on how easily the toner was applied and fused to the paper. If you cannot avoid applying a large amount of a solid colour, applying a filter, or breaking it up with text or images will help to counteract any uneven application.
Unlike a litho press, digital printers cannot apply spot colour, therefore pantone inks can’t be used. However, CMYK can achieve an effective representation of those colours. Since digital printing is cheaper, you can proof these colours and adjust them based on which is closest.
Screen Printing:
Introduction
Screen printing is a technique most suited to flat surfaces, in which the image is transferred onto a screen, with the areas not to be printed masked ot of it. The squeegee is a tool which presses the ink through the mesh screen and onto the stock.
If you’re using more than one colour, you will need to use separate screens for each colour. It is possible to create more intricate designs when screen printing, but this method is most suited to bold graphic designs. The more detailed the design, the more complicated the breakdown of colour and screen preparation. Simple colour designs are usually inexpensive in the college as all you are paying for is the inks.
Screen printing is considered very useful commercially as you are able to create many prints before reapplying the ink.
It is also a convenient method of printing larger designs, as it is easier to make adjustments than large scale digital printing. Similarly, it takes much longer for the colours on a screen print to dull, they remain sturdy.
On top of this, screen printing has a wide range of utility and can be applied effectively to a huge variety of formats, ranging from fabrics to adhesive labels.
Prep
Ensure that your chosen image is 300DPI (dots per inch) which is the amount that a screen contains. The higher the DPI the higher the resolution. You can change the DPI on photoshop, but be aware that scaling the image from an initially low DPI will cause the final artwork to be very pixelated.
It is vital that while using Photoshop, each colour you plan on using is separated to it’s own layer, including the background colour. If you have used Photoshop effects, you also need to separate these as another layer.
Be sure that the artwork you are printing has the exact dimensions of the print you want to produce. This may seem obvious but it is vital to ensure that everything measures up or the print will be a waste of your time and money.
Stock
The most effective screen printing results are achieved when using heavier stocks. While the grain of your stock will alter the outcome of your print, it can often lend itself to the aesthetic of it. Coated stocks are not advised as they can’t absorb the ink as effectively as uncoated.
There is a very wide range of paper and cardboard stocks that are suited to screen printing, depending on the need or function of the screen print. Have a look around before choosing your stock as there are plenty of inexpensive options, but ensure that they are stocks that can absorb the ink.
It is advised to use stock between 250 and 350 gsm. The more absorbent the paper is, the sharper your image will appear. Fabrics can be effective for screen prints, but you will need to check for a grain and a ‘right’ or ‘wrong’ side, although it is usually only heavier fabrics where this is important.
To get an effective print on thinner stocks, you will need to use oil-based inks as oppose to the water based inks used of heavier stocks. Oil-based inks are thicker, harder to clean up, much more expensive, and cannot print onto fabric.
Tips
Take your time. The inks do not dry in a matter of seconds so it is not necessary for you to rush the process. On top of this, rushing will normally create a mess that doesn’t need to happen. The inks will dry if left for a long period of time, but not if you work at a steady pace, so remain calm.
Wear comfortable shoes. This may seem like a trivial matter but screen printing is quite a physically demanding process and you will spend a lot of time standing up and hunching over. Take regular breaks to stretch.
If you have the time, consider watching someone else print. You may pick up useful techniques from watching or helping other people
The basics or screen printing are always the same, but there is not only one way to do it. There are a variety of techniques that can vary your outcome, so don’t get hung up on one method in the print room.
Keep your prints simple. You don’t need to go nuts with detail and equipment to produce a good print. in most screen printing designs, the simpler the better. Similarly if you do want to mix things up, there are plenty of online tutorials you can look at.
Consider bringing a friend to the print room with you. Sometimes this will help you by seeing how other people work and you could pick up some tips from their methods. Everyone works differently so you could experiment with what way works best for you.
Consider keeping lots of scraps of paper or paper towels around you as they can be useful for both test prints and to quickly rectify a mistake. This will help the process run more smoothly as you won’t have to frantically find something to clear up a mistake with.
Think outside the box. By returning to the same stock and method with each print you run the risk of your work appearing repetitive. Screen printing allows you to print on a huge variety of surfaces, so you’re not limited to plain fabrics or paper.
Try to print on a regular basis. Screen printing can come easily to some people but not always to others, but if you’re in the latter don’t allow it to discourage you. Printing regularly will give you a better sense of how you work, with the inks, the screens, and in your space.
In screen printing, tape will become your best friend. It will help you keep ink from leaking, help register your print and aid the application of ink to your screen. Don’t enter the studio without a roll handy.
Considerations
When screen printing type, you will need to convert the text to outlines, this way they’ll be interpreted as ‘paths’ instead of text. To do this you select all the text, go to ‘Type’ on the top menu bar and select ‘Create Outlines’.
For your first screen print, keep it simple. Geometric shapes are a good starting point, and as you become more accustomed to screen printing, you can add more intricate detail to your designs.
Leave to dry for as long as possible; the longer the better, and take care when lifting the screen off your stock as it’s likely to smudge if done so hastily.
Inks can be a nuisance to clean up, particularly out of clothes or off of some of the flat surfaces you will be working on, so be sure to clean up spilt ink before it dries. This will just make it less trouble to clear away.
Embossing
Introduction
Embossing is an extremely simple and inexpensive example of a print process. It is probably one of the cheapest way to alter the first impression of an image, transforming a design so make it appear elegant and ornate when raised on the surface. It can enhance the look and feel of a huge range of surfaces, from paper or card to cloth or even metal.
There are several aspects to Embossing that need to be considered and attended to before executing the process itself, and this booklet will guide you through all the different elements and variables that you need to consider in your preparation for embossing, including the dies to be used, the surface being embossed, the preparation of your design for embossing, and of course, the details of embossing itself.
Embossing is produced using the same equipment as used for letterpress. It requires film and metal dyes to allow the image or type to be raised off the paper. Debossing is a similar print process , using the same equipment, but instead pushes down the image so that it sinks into the paper. Embossing comes in several formats; blind embossing (no colour), tint embossing and glazing, each of these techniques ad elegance to any paper surface.
Preparation
Before you can start to emboss you need to have your desired image printed with the embossed portion of it filled in a solid colour (eg. 100% Cyan, 100% Magenta or 100% Yellow). In this instance, it is probably most useful to use Magenta as it is the most vibrant (unless you’re using a lot of magenta in your design). Since this needs to all be one colour, change the embossed portion to ‘spot’ colour.
It is crucial for the emboss to have a very crisp edge, so should be created as a vector in Photoshop. Because of this if you are using a typeface in the image it is advised to choose your font based on the sharpness of the edges.
You will need to manually set the colour to ‘overprint’, which can be done on Illustrator by selection ‘Attributes’ under the ‘Window’ menu. Here you can select the item being embossed and check the overprint option.
When you check the ‘Overprint Preview’ it should show the embossed portion in a darker colour. When the preview is off the embossed portion should read 100% M. When selecting ‘Separation Preview’, it will appear more transparent.
Stock
There are many things to consider when selecting stock for embossing, including the characteristics of the surface, grain, weight, inks and coatings to be applied. Generally the stocks that embossing has the best effect on are those that are uncoated and heavier, as the heavier stocks will provide more dimensional depth and detail.
Be careful when using stocks that are textured, as when it is a pronounced texture it will have to compete with the embossed image. When doing a blind emboss, a lightly textured stock produces the most effective results.
Consider the direction of the grain of the paper, as going against it can result in some cracking problems. This is also a problem when using coated, varnished or lighter stocks as they do not have as wide a scope to stretch. However, embossing with a foil covering rather than ink can help eliminate cracking on coated stocks.
Using recycled paper can cause inconsistencies in the appearance of the embossing, because the high content of recycled fibres causes the stock to be weaker when exposed to heat and pressure. Try to avoid using recycled stock, but if you do, ensure that it has less than 30% recycled fibres.
Long-fibre stocks are considered best for embossing as they can accommodate for a wider variety of embossing dies (particularly deep dies). When embossing materials for packaging, sulphate and foils are the best stocks.
If the stock being embossed is very thick then you may need to increase the depth that will be tooled into the die, providing more definition to the embossed image. An increased depth will help compensate for the thickness of the stock, it’s resistance, and it’s memory (how long the stock will keep before returning to it’s original shape).
Tips
Embossing is a decorative process, and in some instances there may be no need for it. Embossing can be considered ‘too much’ when the design is particularly intricate or detailed. The most effective embossed designs are usually with lettering or more simple images. However, copper dies to provide better reproduction of detail than other materials.
Take some time to consider what other finishing processes are available to you because, again embossing may not be necessary if you are including a finishing process like foiling, which already draws the eye towards it. Such as with many design problems, often the simpler really is the better.
When creating your copper plate for embossing, always check and double check that there are no bumps, wrinkles or bubbles as this will cause the copper to indent in places that were not intended, as the copper will expand when exposed to heat.
If you are unsure in making your die selection, ask one of the tutors in the print room. They understand that the sharpness of detail in terms of embossing and foiling is extremely important, and will be able to make informed decisions based on the dies, your design and your chosen stock.
If you wish to emboss a more detailed image, it will work better with a shallow depth, whereas bolder images can handle a deeper emboss. However, the stock will play a huge role in determining the appropriate depth for your image.
Considerations
When selecting your dies, refrain from choosing bevel edge dies, particularly when combining embossing and foiling, because the foil is not compatible with a beveled edge. These dies are generally made up of brass with the edge of the image sloping 30 to 50 degrees, which means you can also not use magnesium with the dies.
Scorching and blind embossing is most effective using multilevel sculptured dies. Find advice from someone in the print room when selecting your dies for the image )or vice versa), as they will understand the importance of the sharpness of detail when embossing or foiling.
Finely detailed images will produce the best results when embossed at a shallow depth, while bolder images look most effective when deeply embossed. The stock you choose in conjunction with the image will help determine the depth of embossing die you require.
Take care when considering the format in which you are embossing. In some cases it may be too much for a design and take away from it. Consider other finishing processes, don’t just emboss a design to emboss it.
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