Weed bongs vary in material, shape, size, and color. Some of the most used materials for the creation of fabric bongs include glass, metal, and ceramic. Most of the bongs for sale are made of glass. However, some homemade weed bongs are made of objects like plastic bottles, vases, beer bottles and so on. However, it is not recommended that you use a plastic bong due to the toxins produced when the plastic is heated. Some people come up with their out-of-the-box ideas and invent bongs by using extraordinary stuff like fruits, vegetables even bread!