BRIEF INSTRUCTIONS FOR CASTING LOW RELIEF SCULPTURES WITH PAPER PULP
We assume that you are using Twinrocker casting pulp, Ready-To-Use, cotton linters #87, beaten MC (medium coarse) with sizing and methylcellulose.
1. ADD WATER: Take some pulp out of the bag and add water, two or three three times as much water as pulp.
2. STIR the dilute mixture of cotton pulp and water vigorously with your hands until it's as smooth as it can be, considering it is plant fibers and water.
3. THE MOULD: If your piece is a medium to large bas relief, you will need sides on the mould about 1 inch high in order to hold enough pulp and water for your casting. Be sure that your mould is not absorbent to water. If it is made of plaster, seal it with shellac or varnish.
4. PARTING AGENT: Be sure to coat any mould with a parting agent, either the paste wax or a silicone spray for door locks.
5. POUR THE PULP & WATER MIXTURE INTO THE MOULD: Be sure there's plenty of water in the mixture you pour.
6. 'PATTY CAKE' (PAT, PAT, PAT) THE PULP WITH YOUR HAND: This may be the most important step in the process. By patting the pulp directly with your hand, you jiggle the pulp fibers down into the detail at the bottom of the mould. This is also why it is so important to have enough water in the pulp mixture. When you are learning, pat the pulp three times as much as you think you should.
7. TAKE THE WATER OUT OF THE PULP MIXTURE WITH A SPONGE: Begin by laying a real cellulose sponge on top of the pulp and water mixture, when it has absorbed as much water as it can, squeeze it out and continue working the sponge slowly around the sculpture, absorbing water and squeezing out the sponge. Slowly begin to PRESS as you absorb the water. Continue to do this until you are PRESSING AS HARD AS YOU CAN WITH THE SPONGE ON THE PAPER PULP AND TAKING AS MUCH WATER OUT AS YOU CAN.
8. DRY THE CASTING in the air. Bear in mind that warping is caused by one area (or areas) drying before the rest of the piece. If you place it in the sun or use fans be sure to cover the surface of the casting with something absorbent like a terrycloth towel or blotters. A warm, dry chamber with little air movement is ideal, like a closet with a dehumidifier in it. With a medium to large mould, you may need to weight the edges of the casting to keep them from warping up. DON'T TRY TO TAKE THE SCULPTURE OUT OF THE MOULD UNTIL IT IS COMPLETELY DRY!!