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Introduction
An explanation of screenprinting, and the benefits of learning the process.
How To Screenprint Explanation and instructions on how to screenprint in general, explaining both the process of cleaning and producing a screen, as well as the process of printing.
Silk Screen Printing Acrylic Ink p25
Neon Ink p27
Metallic Printing p29
Spot Varnishing p31
Fabric Screen Printing Foiling p35
Flocking p10
The ‘Wow’ Factor Phosphorescent Ink p18
Thermochromatic Ink p20
Interviews Neil Owen - Technician p22
Will Bryant - Designer p25
Glossary
A glossary of screenprinting related words & terms.
Scratch Card Printing p21
“Before printing was discovered, a century was equal to a thousand years.� Henry David Thoreau 1817 - 1862
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print prÉŞnt/ verb 1. To produce (books, newspapers, etc.), especially in large quantities, by a mechanical process involving the transfer of text or designs to paper.
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How To Screenprint
This section will teach you the process of screenprinting (both silk and fabric screen). Not only will you learn how to physically print, but also essentials such as cleaning, exposing and safety precautions.
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1. Preparation Screen The first step with screen printing is to find a screen. When working with paper, you generally would use a silk screen. However this is different for foiling and flocking, where a fabric screen is used. In order to have enough room to print, you should find a screen with a border of 10 centrimetres or more. The easiest way to measure this is a rough ‘hand sized border’ around the image you intend on printing.
Print Out You should print out your image in greyscale, and solid colour. If you want to use gradients, the image should be converted into a half - tone. The area which will expose and then print, is the area printed black. Believe it or not, but a badly printed image before exposure can ruin your print. If your print has defects or not printed properly, this directly be seen after exposure.
Ensure you work with print marks when using more than one colour printing. This can help align each layer or print perfectly. 5
COMMON MISTAKES The use of an incorrect screen. It’s common to pick up a fabric screen, and prepare it for printing, when a silk screen would be more appropriate. You can still use a fabric screen, however much less detail can be achieved. Too much detail. Unlike digital print, less detail can be achieved when printing. Ensure that you do not use an ultra - thin typeface, or stroke. In terms of a typeface, nothing below 8pt can be easily printed. Similarly, strokes that are below 1.5 pt size can prove difficult to print.
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Apply B-Strip, rinse, then apply B-Solve.
2. Stripping The Screen More often that not, you will have to strip a screen that had already been used, in order to exposure your design onto it. There are two chemicals involved in stripping: B- Solve & B - Strip.The process of stripping a screen is as follows: 1. Sponge on the B - Strip onto the screen, both sides of screen. Rinse with the hose, then thoroughly rinse with a power hose. 2. Sponge on B - Solve, then leave for 10 minutes. After waiting, rinse screen with a hose, then thoroughly rinse with a power hose. 3. Use washing up liquid to clean each side of the screen. This is done to remove grease, and vital.
Top: The tubs of B Strip and B Solve.
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Top: Emulsion on screen, being removed with B - Strip. Mid - Left: B - Solve being left on the screen for 10 minutes. Mid - Right: Degreasing using washing up liquid. Bottom: The clean and blank screen.
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FORGETTING SOMETHING? There are some serious safety precautions that have to be taken to use these chemicals. As the chemicals are used to strip emulsion, a similar effect could be replicated on your skin. The fumes are also equally as bad for you. The use of the water jet can be loud, and can damage hearing. In summary, everything can cause some sort of damage. It is vital to wear rubber gloves, a coat, goggles, and a respiratory mask.
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3. Applying Emulsion Due to the emulsion being photoreactive, it will react to light. Applying emulsion should be done in a dark room, with no direct exposure to light. The emulsion is extremely difficult to get out of clothing, and it’s suggested to wear an apron when performing this task. The process goes as following: 1. Pour emulsion generously into the scoop, spreading it up and down the width of the tool. 2. Hold the scoop next to the propped up screen, and slide upwards. 3. After reaching the top, go over your emulsion coated screen, scraping excess. 4. Clean the scoop, and leave your screen to dry in a heated cupboard for 30 minutes.
4. Exposing the Screen You should ask for help when exposing, unless you know exactly what you’re doing. The result of an over - exposed screen means you would have to repeat the last 2 steps again. Inversely, an under - exposed screen will result in nothing being printed through the screen. Different exposure times are given for either fabric or silk screens, as well as the stock you have printed onto to expose (light could pass through thinner paper easier, and vice versa). Make sure the exposure screen is clean before using it. Exposure times can be seen on the right. After exposure, you need to wash the screen with water, then remove grease with washing up liquid and water. Ensure the screen is left to completely dry before screen printing.
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EXPOSURE TIMES
1 Light Unit = Approx 3 Seconds
80 Gsm Paper (Regular Printer Paper)
Fabric Screen
Silk Screen
Laser toner - solic black image
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170
Laser toner - greyscale image with tones
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170
Inkjet toner - solid black image
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170
Inkjet toner - greyscale image with tones
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170
Photocopier toner - solid black image
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170
Photocopier toner - greyscale image with tones
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170
Laser toner - solid black image
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Laser toner - greyscale image with tones
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Acrylic paint
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Indian Ink
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Pen Drawing
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Laser toner - solic black image
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Laser toner - greyscale image with tones
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Inkjet toner - solid black image
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Inkjet toner - greyscale image with tones
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Photocopier toner - solid black image
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Photocopier toner - greyscale image with tones
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Tracing Paper
Acetate
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5. Choosing a Bed
Top: A standard vacuum bed. The button to turn the vacuum on is positioned just on the left side (near where you can see the tape is) Bottom - Left: The holes in the bed which act as the vacuum. It is VITAL to not use a PVA substance on these beds (used in foiling & flocking), as the glue will block these holes. Bottom - Right: The weights positioned behind the screen. You should play around with these, ensuring when you pull the frame down, it will stay down. Inversely, when you lift the frame up, it should stay up.
More often than not, you will probably be using a vacuum bed. However, this section is to show you the types of screen printing beds available, and when they would be appropriate to use.
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This is a similar, but slightly different vacuum bed. It works in the exact same way as the previous, but has an arm attached to the bed. You can clamp your squidgee into it, which slides back and forth. This will work well if you’re screenprinting at mass.
This type of bed is the simplest. As previously mentioned, you cannot screen print glue through the vacuum beds. This type of bed uses a simple clamp and a solid surface to print, meaning there is nothing to ruin.
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6. Preparing to Print One major issue with screenprinting (unlike digital print) is time scale available for print. Things can be digitally printed until the ink runs out. But with screen printing, ink can dry and block the screen, meaning they have to be cleaned before using again. For this reason, preparation before starting to print is key, in order to produce as many prints as possible.
1. Positioning the Exposed Screen Correctly Believe it or not, this can be hugely important to get right, in order to produce your desired print. If the screen isn’t placed over the section with holes in it, your stock won’t be sucked down and held in place. If the screen isn’t clamped properly when printing, it can move around and produce a blurred image.
Position what you are printing landscape. This will mean less distance will have be covered at once, meaning you will print quicker. 15
2. Clamping The Screen Down Ensure this is done with the frame facing upwards. The first step is to secure the top horizontal bar. You can then fit your screen in, and secure the lower horizontal bar. Use the clamps to lock the screen in further. The best way to check your screen is clamped in properly, is to pull at it. If there is still some movement, tighten everything up more.
FORGETTING SOMETHING?
Tape! As you can see in the image above, forgetting to tape up the screen is something even the most experienced printers can make. Tape is used to hide areas which aren’t coated in emulsion. If you were to print without taping the edge, ink would print through directly onto the bed. Something not fun to clean up.
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7. The Printing Having set everything up correctly. This process should be simple. The choice of ink and finishes is important, but this will be covered in the next few sections. The Process 1. Choose a squeegee which is slightly bigger than the width of the area you intend to print.
3. With pressure, drag the squeegee and ink towards you, across the screen.
2. Deposit ink just above the area you intend on printing, spreading it across the width of the squeegee.
4. Lift the frame slightly, so it’s not against the bed anymore. Then push the squeegee up to where you started again, dragging the ink with it. 5. Repeat this motion until you have finished printing / ink dries in the screen. 6. Wash your screen and squeegee, and leave both to dry.
COMMON MISTAKES Flooding the screen. This is when you print over the print multiple times, printing back and forth. The result is a print with ‘blurred’ looking lines. If you feel the print is not vibrant enough after printing once, it’s best to print over towards you each time. Not pressing down hard enough. Don’t be shy to apply plenty of pressure to the squeegee. The result of not applying enough pressure is an uneven print, where only sections have been printed. From left to right : The process of screenprinting.
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You should only ever print towards you. Pushing away from you is for preparing ink for another print.
Not enough ink coming through the screen. There are two main reasons for this. If it happens when you first start printing, you simply need to persevere and keep printing, and the ink will begin to come though. If you have been printing for a while, the ink may have dried in the screen, blocking further ink from coming through. The best thing to do is wash the screen, leave it to dry, and start again.
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8. Registration Depending on the type of print you’re producing, this has differing importance. If you intend on producing a series of prints with 2+ layers of ink, or printing double sided, this holds huge importance. This is also important if you want to maintain consistency in terms of position with all of your prints. Printing Crop / Registration Marks. When chosing your design, printing crop marks will allow you to cut your print straight, if there aren’t any distinct edge. When printing 2 + colours, you can see how aligned each print is (or how off the image is printed). If you do not print crop marks, do not worry. If you’re careful, you can use a black marker to create your own crop marks, which you can put on your print out before exposure.
Printing onto Truegrain. True grain is a plastic sheet, which is to be printed on before printing onto stock. You print onto it, as you would onto paper. Next, you place your paper under the truegrain, lining it up with the image printed above. Turn on the vacuum bed so the sheet stays in place, and use tape to frame the edges of the paper. The tape acts as a jig, making placing sheets in the right place much easier.
Make sure you remove the truegrain before printing onto the stock. 19
Top: Image printed onto true grain, with paper slotted underneath.
Bottom: Tape marking out where the paper should be placed.
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9. Repairing One issue that can happen after mass production of prints, is the screen starts to deteriorate. Emulsion can start to peal off, resulting in badly printed images. However, instead of having to strip the screen and start again, there is an easier approach to take: 1. Pour a small amount of photo sensitive emulsion into a pot, and grab yourself a small brush. 2. Paint onto the areas of the screen where emulsion has been removed. 3. Re - expose your screen for 30 seconds.
Top: Image printed onto true grain, with paper slotted underneath.
Bottom: Tape marking out where the paper should be placed.
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For a quick repair, you can use parcel tape on the underside of the screen. This isn’t as accurate as re - applying emulsion.
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Silk Screen Printing
An introduction into the inks and finishes available when working with a silk screen.
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Acrylic & Binder Having learnt the process of printing, you are now ready to apply what you have learnt to printing. Generally, the rule of thumb is to use a ratio of 60:40, acrylic to binder. The use of a higher ratio of acrylic will result in more vivid prints, but reduces the amount of prints that can be produced before the screen blocks. For a much higher production rate, a higher ratio of binder can be used, stopping the screen from blocking as quick.
What You Will Need: 1. Black & white print out 1 Roll of parcel tape 1 Roll of masking tape Photo sensitive emulsion Paper binder Acrylic paint of choice Sheets of stock
Equipment: 1 Silk screen 1 Squidgee 1 Emulsion scoop 2 Spoons 1 Vacuum bed True Grain
Difficulty: 05/ 10 Consistancy: 09/10 Estimate of Prints Produced Before Screen Blocking: 20 - 30
Below: The combination of acrylic with binder at a ratio of 60:40 Top - Right: A print using the 60:40 ratio. This works well on a light colour paper, with the use of a darker acrylic. Bottom - Right: A white print on a darker stock. The suggested ratio of acrylic to binder is more of a 75:25 mix. This is so the white appears vibrant, and doesn’t dry so clear.
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Neon Most digital printers (exlcuding spot - printing) cannot produce a neon finish. Due to neon - acrylic inks being produced, neon can be printed through a silk screen. There is a variety of neon acrylics available: Neon Orange Neon Red Neon Yellow Neon Pink
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Below: Neon orange ink printed onto a grey stock.
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Acrylic, Binder & Metallic Powder
What You Will Need: 1. Black & white print out 1 Roll of parcel tape 1 Roll of masking tape Photo sensitive emulsion Paper binder Acrylic paint of choice Metallic powder of choice Sheets of stock
Again, something hard to replicate with digital print. The use of metallic flakes can give a unique, reflective quality to your work. The process is the exact same as in the previous page, but a small spoonful of powder is Difficulty: 06/ 10 added into the mix. Consistancy: 09/10 A variety of metallic powders are available: Estimate of Prints Produced Before Screen Gold Blocking: 20 - 30 Pearlescent Gold Silver
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Equipment: 1 Silk screen 1 Squidgee 1 Emulsion scoop 3 Spoons 1 Vacuum bed True Grain
Left: The types of metallic powder that are available Top - Right: Pearlescent Gold Powder Mid - Right: A gradient print, composed of green acrylic, binder & pearlescent gold, and red acrylic, binder & perlescent gold. The metallic effect is most effective on a black stock.
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Spot Varnishing This is the first process we have looked at, that doesn’t involve acrylic. Spot Varnish is exactly what the name suggests - a varnish coating, adding gloss. Spot Varnish can look great when printed over a straight acrylic print, or even just on it’s own. Spot Varnish is by far the quickest drying finishing method. Preparation is key.
What You Will Need: 1. Black & white print out 1 Roll of parcel tape 1 Roll of masking tape Photo sensitive emulsion Spot varnish Sheets of stock Difficulty: 09/ 10 Consistancy: 06/10 Estimate of Prints Produced Before Screen Blocking: 5-10
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Equipment: 1 Silk screen 1 Squidgee 1 Emulsion scoop 1 Spoon 1 Vacuum bed True Grain
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Fabric Screen Printing
An introduction into using a fabric screen, looking at the two main uses: foiling & flocking. The reason why a fabric screen has to be used is due to the PVA not fitting through a silk screen. The process of developing a screen is the exact same, but a different exposure time . To find the appoproate exposure time when working with a fabric screen, consult page 12.
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Foiling Foiling is a unique process, where heat is applied to a printed adhesive, creating a foil layer wherever printed. It’s suggested to only print block colours, staying away from gradients & half - tones. A large selection of foils are available: Standard Colours - Red, Blue, Green, White, Black, Etc. Metallic Colours - Gold, Silver, Copper & Holographic
What You Will Need: 1. Black & white print out 1 Roll of parcel tape 1 Roll of masking tape Photo sensitive emulsion Printing adhesive Any choice of foil Sheets of stock
Equipment: 1 Fabric screen 1 Squidgee 1 Emulsion scoop 1 Spoon 1 NON Vacuum bed 1 Heat Press True Grain
Difficulty: 07/ 10 Consistancy: 05/10 Estimate of Prints Produced Before Screen Blocking: 15-25
Left / Below: Images of the heat press. The press is 1 degree off, but this proves difficult to get exactly right. One degree either side off makes very little difference. Top - Right: Clear foil being pealed off, once the sheet has cooled of course.
The Process 1. Develop a screen, as you would with a silk screen. 2. Instead of printing an ink, use a printing adhesive to print your image, then leave your print to dry. 3. Set up a heat press to 160 Degrees Celsius, with time set to 12 seconds. 4. Once the heat press is ready, place foiling on top of your print, with the foil facing upwards. 5. Wrap a few layers of newsprint around the sheet, then place onto the heat press. 6. Pull the handle down on the heat press, applying pressure. 7. When the timer is up, remove the print and leave to cool. Once cooled, slowly unpeel the foil.
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COMMON MISTAKES Applying over a water based ink. If you intend on using acrylic and foiling together, it is suggested to ensure each layer does not merge / sit close to each other. The combination of heated foil and acrylic can result in a gluey mess. If you intend on using both a normal ink and foil, you should use an ink which isn’t water based. Using the heat press at the wrong heat / time. It’s important to be strict on both time and temperature. Pressing for too long / too high of a temperature can result in the foiling bubbling, or even burning. Inversely, a shorter time/ low temperature does not help the foil transfer properly. Aligning / Applying the foiling incorrectly. You should entirely cover your print in a square or foil, instead of trying to cut shapes out. Foil is extremely fiddly, and when in place, can easily become misaligned. It’s best to include a an extra 1cm border when cutting your foil, to allow for this mistake. Another mistake when applying the foil is to place the foil face down. Just before applying heat, ensure that the shiney side is face up. Being impatient. Foiling can be quite fun and exciting, but please wait for your print to cool down before removing the foil. Removing the foil too early can result in most of the foil being pulled off. You should also remove the foil slowly, for the same reason. Wrong choice of stock. The key to foiling is to use a smoother stock. For some reason, sharper edges are achieved on smooth stock, and rougher edges to something more matte. Considering the use of this process should be considered the same time as your choice of stock.
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Further Examples
Mistakes
Left: Foiling being placed in the wrong position before heat being applied. Above: Foiling taken off too quickly.