Here are some DIY techniques for achieving screenprint capability. they will remove the veil of difficulty surrounding screen printing and guide towards a viable method regardless of budget. I have tried to use tools and materials available at any hardware store and each part of the process is optimized for ease and cost.
The main parts of a screenprinting setup are :
- The screen
- The press and platen
- Curing area
The materials we will be discussing and using are :
- paint mixing sticks
- 1x1 lumber
- stock laminated shelf 12x36
- Extruded aluminum window screen kit 60"
- sheer polyester drapery material or screen of your choice
- wood glue
- sodium dichromateor photo emulsion
- latex paint
- diatomaceous earth
- parchment paper and oil or transparencies
- Sharpie oil based paint marker
- duct tape
Tools required :
- brad nailer
- staple gun
Step 1: Choose Build Material and Strategy
BASE Should be heavy, stable and well sized
PLATEN - holds the media to recieve the print. it should be very flat and adjustable.
SCREEN polyester mesh stretched onto a frame. this is sold as drapery in many colors and types. i use the cheapest i can find in the thrift store. It can be found on ebay for less than three bucks. its about the same as "100 mesh" for about half the price
SCREEN FASTENER holds the screen frame to the hinge usually with a clamp or bolt, or c shaped clip.
HINGE - allows the screen to be lifted away from the platen to release the print. door hinges can be used or the motion built in with some brackets and bolts..duct tape makes a good lean hinge. so does the clip from a clipboard.
SUSPENSION - what will hold the screen up in between prints? I like rubberband and spring suspension.
I have made presses from many materials , here are some of the best...
paint mixing sticks - these are strong 12" x1"x 1mm wood pieces available in packs of 10 for $1. They are the cheapest material i have found that can be made into screen frames. they are cut to size , assembled, glued , staple gunned allow to dry overnight.
Extruded aluminum window screen kit. Cost about $15 and include corners and the bead to secure the screen . get a couple extra sets of corners and the bead installation tool. Can be cut with a hacksaw , grinder or chop saw.
Pallet planks - can be had for free if you scour the streets and are easy to rip into 1x1 boards. Alternatively purchase 1x1 pine and use woodglue and pin nails to build rectangular frames.
Pvc schedule 80 pipe and fittings - available at any hardware store and easy to assemble into a rugged and sturdy press. cannot be used for screen frames.
Step 2: ASSEMBLY
assemble and combine the basic press parts including
- screen fastener or clamp
- screen frame
Step 3: Stretch the Screens
For accurate prints the screen must be tightly stretched on the frame. for wood frames it can be secured using a staple gun , for aluminum you will become friendly with the bead and its installation tool. Basically begin securing one side and move to the opposite side next, then secure again the other pair of sides. work your way around securing evenly until tight
Step 4: Emulsion Coating
The Emulsion will form the stencil of your image on the screen. DIY emulsion can made with sodium dichromate and woodglue just dissolve 1/4 tsp of dichomate in water and mix into the glue. commercial emulsion is available in many formulations. It is important that the coating is even and complete. I use a little blue squeegee and smooth each side, discarding exceess emulsion as i go. after a few times the emulsion shows a visibly uniform sheen. It must be dried flat and in darkness. I usually throw it in the closet with a fan, but have used a hairdyrer in the bathroom with the lights off . Moisture can interfere with exposure so extre drying time is reccomended. Give it like six hours minimum.
Step 5: Artwork Prep and Print.
Screenprint technology is basically monochrome. Each hole in the mesh will eitherr allow in to pass through or block ink with hardened emulsion. gradients can be achieveed with multi color pulling techniques or layered effects like blending and halftone. Ensure your image prints in mono by maxing out the contrast and converting to grayscale. the master must be on a transparent material and opaque. foolproof masters printed on clear label are available at kinkos for $1 or laser print on transparency is a safe bet .. inkjet or photocopy on copy paper can work if u saturate with oil to make transparent and add a little exposure time. I use parchment all the time treated with baby oil...or shapes can be cut from something opaque, like cardboard and used to block light during exposure.
Step 6: Expose the Screen
The transparent master is held against the screen while uv light passes through, curing the emulsion under the unprinted areas.For best results The master must not move during exposure.glass works to hold the master , so does spray adhesive or a thick coating of oil. only allow light to reach the master side and use a black material to prevent reflected light from exposing the backside. any light source will in time expose your screen. I have used 100 watt incandecent bulb and a flexible desk lamp about 3" from the screen exposed for around 1 hour . common flourescent 2 or four lamp fixtures can be used with exposure times of 15-45 minutes. 500 watt halogen shop lights are hot and need to be at least 12" from the screen surface and burn time will be 5-10 minutes. Solar exposure is effective and rapid, exposing well in under a minute . in direct sun at midday try 30 seconds exposure time.
After exposure run some water onto both sides and gently rub with your fingers. rub and wet a few times over 10 minutes the wmulsion will loosen, then wash away. use a moderate spray (like from a hose with garden vozzle) to knock out the uncured emulsion. blot and get it back out in the light to dry.
Perfect Exposure is difficult and you will usually encounter either under or over exposure frequently. when underexposed the emulsion is not fully cured and begins to wash away. Stop washing when this happens and put in the light (no master). give it a couple minutes and then spray again. when over exposed , little of the unexposed areas washes out this means the master wasnt blocking the light or that light was getting to the backside. theres really no reversing overexposure in moderate cases scrubbing and extended or high pressure spray can help.
Step 7: Press Setup
The printing process will be more pleasant with some preparation. fit the screen to the press and check its motion. check the platen and its alignment to the screen. the screen should hold tight to the platen with little play. prepare pieces of media and have them nearby with some scrap media for test prints (strikeoffs) have a cleanup plan for ink spills and gloves ready. prepare mentally to print.
Step 8: Prepare the Ink
Generally ink is water or oil (solvent) based and air -cure.. Plastisol is an ink that only cures at a very high temperature. diatomaceous earth can be added to most any paint to make a thick and durable ink. Stir all ink or mix until very smooth. pick your ink and an applicator like a butter knife or spoon. also pick your printing squeegee and get a container of water (solvent) and a few rags. place every thing next to the press
Step 9: Pulling Prints
traditional technique calls for a wide squegee and two step flood and pull. I have found that one step pull acn give sharper lines if ample ink is used in any case the screen is pulled down and held tight against the media while the squeegee is used to spread the ink and push it throug any unblocked mesh. as the screen is lifted it will pull away leaving the deposited print. loose media will have to be helled or pulled from the back of the screen. prints are set aside and allowed to cure or expedited with air or heat.
Step 10: Clean the Screens.
Scrape as much ink off the screen as possible. apply water or solvent and remove ink using rags. It will take a few and can be messy. once ink is removed, scrub gently with some dishsoap, rinse and allow to dry. Reclaiming screens is removing all emulsion and ink from a screen so that it can be recoated. emulsion remover is sprayed on both sides until evenly wet. about 15 minute soak is needed to loosen the emulsion and a trashbag can be used to prevent dryin of remover and emulsion which can lock into the screen. use undiluted clorox bleach as a diy emulsion remover.