You may want to cover your tables with newspaper to make clean up easier. To make the hands, each student needs a latex glove (be sure to use thick gloves NOT the thin food service type), then mix up a small batch of plaster and pour it into the glove while the student holds it open. Once their glove it full, have them pinch it closed and hold it up until the plaster hardens (about 10 min). The stiller they can be holding the plaster, the less chances of fingers breaking off once its dry, I have my students tell jokes or riddles while they wait. HINT: You may need to mix up multiple batches depending on the size of your class, try not to mix up to much at one time or it will harden before you get to pour it into the glove. If you have never worked with plaster before, I recommend trying it out on your own before attempting with a class--it's a very manageable classroom material if you know what to expect!
When the plaster hardens you can lay the gloves down on the table and carefully cut the glove off with scissors. You should have a perfect hand shape which may stand up if the bottom is flat enough ( you can sand it flat if its not!). I let these dry completely over night. To clean up any plaster disasters, let it harden and then break it up with a scraper and hammer, through the hardened chunks away. If you want to get it out of the bucket you mixed it in, let it harden and then flex the plastic bucket to pop it off the sides. DO NOT LET PLASTER GO DOWN THE SINK!! I set up a 5 gallon bucket of water for students to wash their hands and any tools in, then just dump that water outside.
Once the plaster is set, use watercolor paints to paint the entire surface of the hands, the plaster will absorb the paint quickly. You can use this as a time to tie in a color theory lesson explaining the differences between warm colors and cool colors or just give them primary colors and have them experiment mixing. Once the paint is dry, give students a selection of fine and ultra-fine sharpie markers to start their henna patterns with. I encourage students to do at least 10 different patterns and to cover the whole surface. They can use the patterns they drew earlier as references on their final pieces.
HINT: If you have broken fingers, they can be fixed! Take a small drill bit and drill about 1/2" into the finger that is broken and also into where it connects. Cut an inch long (or shorter) dowel of wood, such as a shish kabob skewer, dip the ends into glue and fit it into the drilled holes. You can also add a little bit of glue to the plaster surfaces, push the broken pieces together gently and let dry!
!!! B CR8IV!!!