Resin Obsession toobies For resin casting are great for creating holes in your resin without drilling holes. Just embed toobies between layers of your resin castings. Once cured, clean any resin that seeped into toobie. The inner diameter of the toobie can fit a 20 gauge wire.
How to use toobies: Pour your resin into half of the mold and let it cast. Cut your toobie to the exact size that you need it to be (the length of the mold--be careful not to cut the toobie too short--you want a nice, tight fit) and place it in the mold where you would normally have drilled your hole. Make sure your toobie is snug, otherwise it may move when your pour your next resin layer. When your entire piece is cast and out of the mold you will end up with a hole in your cast that is perfect for a bead and you didn't even have to drill a hole!
See how you can add toobies to your resin castings here: