Where possible, broken pieces of glass are edge-bonded with a conservation grade epoxy resin. This means that the pieces no longer need to be separated with a 'mending lead' and enables the piece to be returned to it's original size and shape. Conservators clean the broken edges of the glass and then tape the pieces together so they are secure, and so that the resin does not leak out of the cracks and onto the surface of the glass. Small pieces of wax are applied to the outer edges of the breaks to prevent the resin leaking at the sides. This wax is very easily removed. Clear resins are then applied along the crack, and create an almost invisible bond. Resins are also used to create small infills, where fragments of glass are lost.