What follows is a list of links to suppliers of materials which I use when constructing my lightsaber replicas. Many people have requested this information, particularly with respect to RTV mold making and resin casting for the Graflex bulb socket, calc-lenses, etc. I have also listed links to on-line arts and crafts supply stores for items such as brushes, paints, and adhesives. They have their own brand of casting resin, which is very easy to use, but a bit more expensive than other resins.
Some people love it, some people hate it.
I have used it, and have always been pleased with the results. But there are cheaper resins. Since it's easier to use than most, I recommend it for beginners. Not a huge store, but their resin works well. Their site also offers basic information on mold making and resin casting.