Plaster Prints Demo Notes 4/30/16 Marion Bartl, Kate Snow, Loreen Matsushima
Making the plate(s)
Note: make a plaster test plate with the same depth of the plate(s) you will print. This is lets you set the printer to the proper height without risking damage to the real plates(s).
- Mix plaster to a fairly think consistency, think of thick pancake batter.
- Optionally add Elmer’s glue to help prevent cracking, or try covering cardboard with glue.
- Cut cardboard to the shapes you want.
Note: Loreen makes a drawing ahead of time then cuts the cardboard to the shape of the background. The spaces in between the cardboard cutouts become trees and roots (see picture) in Loreen’s plate.
Marion cut a rectangular piece into two parts: bottom was a thick, rough plaster coat for the bluff, top had light plaster coat for the town and sky: see photo.
- To make the plate more durable cut a coated cardboard and glue it coated side out to the first cardboard, cereal box cardboard works.
- Apply plaster to cardboard. The thickness of the coat depends on how much texture and depth of impression you want. The thicker it is the longer it takes to dry.
Note if the plate is thick you will need to use additional mats & foam for printing to avoid breaking the plate.
- Wait for plaster to harden a bit, so it will hold lines but be easy to carve.
- Incise the plaster as desired. Combing it with a serrated knife creates a rain effect. Incise with tools, stamps, and/or press in lace, twigs or leaves then remove (or not), add stencil, etc.
- Take a picture of the final layout so it can be recreated!
- Allow to dry completely. This can take overnight. Do not place in sun or blow dry: faster drying can cause cracking. Be sure the plaster is totally dry/cured or the pressure of the press may flatten it.
- When dry you can add additional embellishments – think Collagraph
Note: Marion used incised aluminum tape to create buildings, see photo.
- Coat to seal, with acrylic mat medium or shellac. An experiment is underway to see how white Waverly Wax water based sealer works.
- If cardboard is thick consider sealing edges with epoxy or additional glue.
- Let additions & sealer dry completely.
- Ink and wipe like intaglio or relief plate or both. Paint ink on, rub in, etc.
- If inking is complex consider using a slow drying ink like Akua.
- Loreen inked & used broken eggshell in Printing Step 4. She keeps a container of small eggshell pieces to ink if bits are needed here or there.
IMPORTANT NOTE: When using a thick plate remove good mats from the press & replace with old mats (which are rolled up under the big table in the clean room). Use the piece of green foam on the bottom layer closest to the print. This keeps the good mats from getting ruined by being compressed too much.
- Set the press height using your test plate. Place test plate on a sheet of newsprint, cover with newsprint, set press to approximate height, try it and adjust until you get it right. See note in step 5 below.
- Put a piece of newsprint or other paper with your registration marks on it on the press bed.
- Place your plate(s) according to the registration.
- Place your dampened paper face down.
NOTE to avoid a wrinkled print if the plate is thick & smaller than the paper: take folded strips of clean fabric and place over edges that are not to get printed, and place fabric between the paper and the foam pad next to the plate edges. Use thick printing paper for best results.
- Run through press.
- Carefully remove paper from plate: paper may tend to stick to intricate plates.
Tips for separating the paper from the plate: remove the plate & paper together to the counter before separating.
Spray the back of the paper lightly with water and pressing in with a sponge may help release the plate. Spraying water between the plate and paper one person spraying one person lifting may help. To absorb extra water blot with blotting paper.