I personally made these by hand, with no molds. These stitch markers are made from polymer clay, baked for hardness & durability with a glaze applied. A one of a kind item, they look similar but no two are exactly alike! The penguins are approx. 1/2" tall. This set fits up to a size 10 US knitting needle (9 mm). They come hooked on a 2 inch kilt pin which can be used as a stitch holder!