I did this at TechShop Menlo Park. http://www.techshop.com
Using resin and foraged natural items we made fun jewelry! You can also make paper weights, fridge magnets, belt buckles, wall pieces, etc.
Step 1: Make molds
I used the vacuum former to heat and form sheets of plastic (from Tap Plastics you can get sheets of Polypropeline) to make molds. I like working with nature so I used pieces of wood, bark and pine cones cut in half lengthwise. I had to cut the pinecones or else the plastic would wrap around them and I wouldn't be able to get them out. No undercuts. I also got one pre-formed mold sheet to accomodate many small resin pieces to be made.
Step 2: List of ingredients
This is what I got in preparation for casting day: Clear lite casting resin, catalyst, blue nitrile gloves (make sure to not use thin latex gloves as the resin will burn through them and end up on your hands), measuring cups of different sizes, wooden stir sticks, resin spray and resin dye. All these items are conveniently found at Tap Plastics. I set everything up outside because resin smells toxic and does give off toxic fumes especially once catalyst is introduced.
Step 3: What to cast?
Once again I love working with nature so I went foraging for natural items. I gathered a bunch of dried leaves, flowers, branches fuzies, grasses, puff balls, feathers, prickly balls, etc.. You can resin cast pretty much anything as long as it is dry. Moist items will interfere with the curing process and with change color when casted.