Subtractive sculpture is the oldest form of sculpture and involves removing material, as in wood carving or stone sculpture, to create a finished work.
Note: NEVER POUR PLASTER DOWN THE DRAIN.
Never touch dry plaster with wet hands or let water drip into the plaster source.
Step 1: Procure a clean bucket. If you find a dirty bucket, clean it out completely before use.
Step 2. Mix plaster, vermiculite and water according to these ratios: 3 parts vermiculite, 2 parts Plaster of Paris, 2+ parts water. Mix together dry ingredients in a large bucket. Add water, and let sit until it stops bubbling (a minute or two). Mix well with hands, squeezing out all the lumps.
Step 3. After mixing, immediately pour into your mold. Tap sides of the mold to bring air bubbles to top.
Step 4. Allow to harden (over night) and cover molds with plastic bags to keep fresh until ready to use.
Step 5: CLEAN YOUR BUCKET IMMEDIATELY. Clean other plaster-caked items immediately. DO NOT POUR PLASTER DOWN THE DRAIN. Chunk solid pieces into the trash, and wash out in the designated plaster-washing bucket. CLEAN EVERYTHING THOROUGHLY.
Step 6: SERIOUSLY, DO NOT POUR PLASTER DOWN THE DRAIN.
Step 7. When the mixture has hardened, carefully remove mold. TAKE A PROGRESS PHOTO
Step 8. As the material is very soft and will remain damp, you will use carving tool to subtract the plaster away. When the work is finished for the day, return it to the plastic bag to keep it moist until the next class period.
Step 9. Once the desired shape is achieved - TAKE A PROGRESS PHOTO
Step 10. Cover again with the plastic bag for Part Two of your project.