A preform is an intermediate product that is subsequently blown into a polyethylene terephthalate (PET) container. Preforms vary in neck finish, weight, color and shape, and are specifically designed to meet the needs of diversified market segments.Preform weight depends on the end container’s desired volume.company offers a full assortment of polyethylene terephthalate (PET) preforms for skincare & personal care packaging,household & cosmetics products.