Beginner’s Guide to Screen Printing

Just getting started in screen printing? Our experts at MacDermidConnect are standing by to walk you through the professional stencil-making process, from preparing a new screen, to creating your stencil, through cleaning your screen for your next project.

 

Visit our YouTube channel for our collection of “How-To” Videos

 

Stencil Making Process 

Step 1: Prepare & Degrease Mesh

Proper mesh preparation is an easy way to save screen printers money, and reduce the number of screens that need to be remade. Degreasing mesh and ensuring limited contaminants is a staple of best practices in screen printing.

  1. Autoprep Gel
    Autoprep Gel
    As low as £136.49

    Autoprep Gel is a ready-to-use micro-abrading/degreasing liquid for new mesh. Autoprep Gel is ideal treatment for all monofilament synthetic meshes, without causing the damage associated with harsh abrasive and scouring powders.

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  2. Universal Mesh Prep
    Universal Mesh Prep
    As low as £84.44

    Universal Mesh Prep is a combined degreaser and wetting agent. Perfect stencils start with properly prepared screens. This helps the mesh to hold as much water as possible which is the key to applying Capillex films successfully.

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  3. Degreaser Concentrate 1:15
    Degreaser Concentrate 1:15
    As low as £163.91

    Degreaser Concentrate 1:55 is a premium degreaser concentrate, water-based and dilutable preparation for the removal of grease and general contaminants from screen printing mesh prior to applying the PLUS emulsions. Excellent anti-static properties and biodegradable - helps to reduce fish eyes.

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Visit our How-To video for more information on this step.


Step 2: Prepare PLUS Emulsion or Capillex Film & Coat 

Starting with a degreased screen, prepare PLUS emulsion according to the instructions for the particular emulsion chosen, be it a dual-cure, SBQ, or SBQ hybrid.

DUAL CURE EMULSIONS

Dual cure emulsions require adding diazo sensitizer to the emulsion. After carefully cutting the top off the diazo packet, pour all of diazo sensitizer to the emulsion, and mix until the emulsion is a uniform color, making sure to get the sides of the pail. Leave the emulsion for 2+ hours to de-gas, the process by which the air bubbles introduced during mixing stage rise to the surface and separate from the emulsion. This is done in the pail before pouring the emulsion into your coating trough. Pour the mixture slowly to prevent bubbles and spills, then coat the mesh, being sure to apply the final coat to the squeegie side to ensure the emulsion gasket is created on the print side of the screen.

  1. Plus Ultra
    Plus Ultra
    As low as £116.41

    Plus Ultra is a universal emulsion for the highest quality applications with water-based inks or UV curing and solvent based inks. PLUS ULTRA is a highly durable water and solvent resistant emulsion that is ideal for high quality textile printing. The easy reclaim of this emulsion means that less stencil remover is required, making the process more sustainable.

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  2. Plus Gold
    Plus Gold
    As low as £185.27

    Ultra-high quality red dual-cure emulsion designed for solar cells and other high specification screen printed electronics applications.

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  3. Plus 8000
    Plus 8000
    As low as £126.46

    PLUS 8000 is a Premium quality dual-cure emulsion with superior razor-sharp edge image reproduction. For all Graphic/Industrial/Textile applications.

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SBQ/PHOTOPOLYMER EMULSIONS

SBQ emulsions, like the Plus 9000 HB, Plus CTS L, and Plus 1 SR, come as a 1-pot solution and do not require diazo sensitizer. Out of the pail, slowly pour these emulsions into your coating trough and apply to your mesh prior to rapid exposure under your exposure unit.

  1. PLUS LAVA
    PLUS LAVA
    As low as £243.94

    PLUS LAVA is a high quality, red fast exposing photo-polymer hybrid textile emulsion with hi-solids 45%, very durable, outstanding results with plastisol, water-based and discharge inks.

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  2. Plus CTS L
    Plus CTS L
    As low as £241.29

    PLUS CTS - L is a high quality emulsion for the latest DMD/DLP Computer to Screen Systems. Developed to meet the needs of the busy graphic screen printer handling large format graphics in automated environment.

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  3. Plus Aqua
    Plus Aqua
    As low as £258.49

    PLUS AQUA is a ultra-fast exposing, high quality, photo-polymer hybrid textile emulsion, very durable, outstanding results with plastisol, water-based and discharge inks.

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SBQ HYBRID/TRIPLE CURE EMULSIONS

SBQ hybrids can be used like SBQs, but have the option to add diazo to improve water resistance. Apply diazo to the Plus LAVA or Plus AQUA like you would for a dual cure emulsion, and the diazo will increase the existing water resistance of the emulsion to provide longer runs and better reliability with water based ink.

CAPILLEX FILM

Capillex film is easy to use and requires minimal training to create reliable results that provide the highest performing stencils in the marketplace. It comes in custom cut sheets or rolls. If needed cut your Capillex film to size using scissors on a clean surface (static will attract dust from surface if unclean). If its a large sheet, roll it up around a PVC tube to make it easier to apply evenly to your screen. If its small use a sheet of glass to help apply over the edge of a table. Start out with a degreased screen and apply the Capillex film to it using the method that makes the most sense for your sheet size. Squeegee off excess water and move to drying area.

  1. Capillex HR
    Capillex HR
    As low as £68.58

    Capillex HR provides exceptionally high print quality and very low stencil profile. Good durability with solvent based and UV curing inks.

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  2. Capillex CX
    Capillex CX
    As low as £239.76

    Capillex CX is a grayish-green Capillary Film specifically formulated for very precise fine line printing in demanding industrial applications. Capillex CX will give a thin, flat, but tough stencil on all coarse to medium mesh counts. It is this thin, flat stencil that minimizes the ink build at the track edges to produce a cleaner more reliable print

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  3. Capillex CP
    Capillex CP
    As low as £193.41

    Capillex CP is a green Capillary Film specifically for ultra-fine halftone and fine line precision printing. The low stencil profile and optimized Rz of Capillex CP gives superb dot reproduction and minimizes ‘skipping’ effects often seen when printing fine halftones with UV inks.

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View our How-To video on YouTube


Step 3: Drying Stencil 

Dry stencil before exposure to remove water from the emulsion mixture. Drying stencils is critical to exposure performance because in a wet stencil, the diazo will choose to cross link with the water instead of the emulsion, and the result will be an insufficient stencil hardness. Ideal conditions are a dust free, light safe room with warm air flow and 35%-45% humidity for a minimum of 1-2hrs (double if printing with water-based inks).

View our How-To video on YouTube


Step 4: Exposing Stencil 

Calculating exposure timing is more important that the type of exposure unit you use. Vacuum pressure/seal, exposure distance from the lamp, and type of exposure lamp are all factors to take into account. In addition each emulsion has a different ideal exposure time, just because one exposure time worked on your last emulsion does not mean it will work for another emulsion.

For instance, the Plus AQUA emulsion exposes 8 times faster than it’s dual cure emulsion counterparts. Alkemi recommends using Alkemi exposure calculator, not something downloadable from the internet, to calculate the exposure needs of your emulsion.

  1. Exposure Calculator
    Exposure Calculator
    As low as £40.16

    Alkemi exposure calculator is a 4-in-1 tool, which allows you to calculate the correct exposure time, check vacuum pressure, wet stencil hardness, and resolution.

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View our How-To video on YouTube


Step 5: Washout and Drying the Stencil 

Washout your freshly exposed emulsion or Capillex film to remove unexposed emulsion from your screen in your washout booth. Focus most of your washout on the print side of the screen to get the cleanest lines, then spray the squeegee side as a final washout. Following washout, be sure to dry the stencil thoroughly before moving to press.

  1. Screen Wash V6
    Screen Wash V6
    As low as £98.94

    Screen Wash V6 is a premium hazard label free, high flash point, low evaporating and low VOC emulsifiable Screen Wash for automatic and manual cleaning (EN12921-3:2005 compliant).

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  2. Screen Wash V3
    Screen Wash V3
    As low as £89.61

    Screen Wash V3 is a premium label free, low odor, aromatic free Screen Wash, part of the Green Screen range as a petroleum distillate free, ready to use with a high flash point and low VOC. Suitable for automatic and manual cleaning (EN12921-3:2005 compliant).

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  3. Screen Wash K3
    Screen Wash K3
    As low as £56.42

    Screen Wash K3 is a general purpose emulsifiable Screen Wash with an affordable price tag. Ready to use medium evaporating ink cleaner, excellent to remove dried-up solvent-based ink in the mesh. Only recommended for manual use.

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View our How-To video on YouTube


Step 6: Block Out (Finishing) 

Block out is an optional step in the screen printing process, and is used to fill any pinholes caused by contaminants or improper degreasing, mesh space not covered by emulsion, or any other imperfections or gaps that need to be filled.

  1. Ruby Block
    Ruby Block
    As low as £270.89

    Ruby Block is a red, fast drying and water soluble general purpose blockout suitable across a wide range of mesh counts.

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  2. Blue Filler
    Blue Filler
    As low as £110.89

    Blue Filler is a water soluble block out filler. Ideal for use with all ink types except water-based systems.

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  3. Green Block
    Green Block
    As low as £115.74

    Green block is a solvent and plastisol resistant blockout and retouching filler. It is a solvent resistant filler that can be used to give a contrasting colour.

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View our How-To video on YouTube


On Press Ink Cleaning

On Press Ink Cleaning 

On press ink cleaning is usually desired when ink begins to harden within the stencil, or after a screen printer takes a break and comes back to the press to finish a job. On press cleaners, or press washes, come in a variety of options based on application. Faster evaporating press washes typically work faster, but because of the chemicals released into the air are typically less health-conscious. A slower acting press wash will be a safer alternative, but won’t work quite as quickly. If your application uses vinyl ink and or need additional muscle, the Press Wash HF will be a huge asset to you.

  1. Screen Opener K2
    Screen Opener K2
    As low as £49.37

    Screen Opener K2 is a general purpose, fast evaporating Screen Opener for on-press ink cleaning. Provides screen printers with a fast evaporating screen opener that helps to keep the screen open when printing.

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  2. Screen Opener D2
    Screen Opener D2
    As low as £69.70

    Screen Opener D2 is a premium fast evaporation Screen Opener and hazard label free to operator. Screen Opener D2 is part of the Green Screen range as a ink cleaner for on-press cleaning.

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  3. Screen Opener D
    Screen Opener D
    As low as £196.54

    Screen Opener D is a premium medium evaporating Screen Opener for on-press cleaning ideal for Graphic and Industrial applications.

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View our How-To video on YouTube

Post Print Cleaning 

Step 1: Ink Removal

Removing ink is the first step in cleaning screens following a screen printing job. Ink acts as a natural barrier between stencil removers and the stencil itself, so failure to remove the ink first will result in poor reclaim from stencil removal cleaning chemicals. Remove ink using one of the below Alkemi Green Screen cleaning chemicals prior to stencil removal for best results.

For use in a dip tank, options like Aquastrip 21 act as a two-in-one ink and stencil remover because both chemicals act on the screen to remove the ink, then stencil in one step.

  1. Screen Wash V6
    Screen Wash V6
    As low as £98.94

    Screen Wash V6 is a premium hazard label free, high flash point, low evaporating and low VOC emulsifiable Screen Wash for automatic and manual cleaning (EN12921-3:2005 compliant).

    Learn More
  2. Screen Wash V3
    Screen Wash V3
    As low as £89.61

    Screen Wash V3 is a premium label free, low odor, aromatic free Screen Wash, part of the Green Screen range as a petroleum distillate free, ready to use with a high flash point and low VOC. Suitable for automatic and manual cleaning (EN12921-3:2005 compliant).

    Learn More
  3. Screen Wash K3
    Screen Wash K3
    As low as £56.42

    Screen Wash K3 is a general purpose emulsifiable Screen Wash with an affordable price tag. Ready to use medium evaporating ink cleaner, excellent to remove dried-up solvent-based ink in the mesh. Only recommended for manual use.

    Learn More

View our How-To video on YouTube


Step 2: Stencil Removal / Reclaim

Mesh is expensive, so reuse of mesh is critical to screen printer profitability. Removing stencils safely and quickly is paramount, so after removing the ink it is important to apply a good stencil remover during the final washout process. Alkemi offers screen printers a dip tank solution with the Aquastrip 21, or a concentrated stencil remover that is diluted with water and applied with a chemically resistant brush to quickly get the job done. Benefits of the concentrated stencil remover are that it saves screen printers money on shipping by reducing weight, and benefits the environment by eliminating the need for excess packaging that would otherwise end up in the landfill.

  1. Stencil Remover Concentrate 1:50/70
    Stencil Remover Concentrate 1:50/70
    As low as £406.11

    Stencil Remover Concentrate is a concentrated product that is diluted with water and used to reclaim stencil making systems, such as direct emulsions and Capillary films.

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  2. Stencil Remover Concentrate 1:20/30
    Stencil Remover Concentrate 1:20/30
    As low as £206.23

    Stencil Remover Concentrate is a concentrated product that is diluted with water and used to reclaim stencil making systems, such as direct emulsions and Capillary films.

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  3. Autostrip Gel
    Autostrip Gel
    As low as £83.13

    Autostrip Gel is a ready to use paste that is an ultra premium stencil remover for manual application with a brush. Fast and effective stencil remover gel for all direct stencils and capillary films.

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View our How-To video on YouTube


Step 3: Haze Removal 

POP!! Oh no, another popped screen due to a harsh haze remover.

Alkemi solved this common screen printer problem with the Haze Remover HV and the Haze Remover Liquid, so no more screens get damaged during haze removal. After emulsion stains, diazo stains, and ink stains leave their fingerprints on the mesh, screen printers need to remove it to return the mesh to like-new condition.

Traditional haze removers, like the Alkemi Haze Hunter, are fast acting haze removers that eliminate these tough stains, but need to be monitored closely to avoid damage tot he mesh. Haze Remover HV is a new breed of haze remover in that you can leave it on overnight, not just 5-10 minutes, and it will crystalize on the mesh to remove stains without risk of damaging screens. Apply Haze Remover HV at the end of the day, then rinse off in the morning, and say goodbye to damaging screens during haze removal.

  1. Quick Haze
    Quick Haze
    As low as £116.79

    Quick Haze is a low-caustic liquid and powerful haze remover for automatic and manual screen mesh de-hazing of ink stains. Fast and Safe.

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  2. Haze Remover Liquid
    Haze Remover Liquid
    As low as £73.01

    Haze Remover Liquid for ink and diazo stains. Used in conjunction with Activator G, A6 to improve ink stain cleaning performance.

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  3. Haze Remover HV
    Haze Remover HV
    As low as £76.32

    Haze Remover HV is a premium Haze Remover, a safer alternative to ‘traditional’ high-caustic hazer removers. Low caustic gel - VOC free, safer for operators and ensures that mesh is not damaged during use.

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View our How-To video on YouTube