Prym Refills for Cartridge Pencil, Yellow, Pink, Black, 0.9mm. These multi-colored Prym refills are for the Prym cartridge pencil. Cartridges for the exclusive marking pen. The fine stroke width of 0.9mm make it possible to trace quilting patterns. Supplied in a sturdy plastic box, which can also be used to keep them safe for storage. Simply reload the pencil and off you go. Seamlessly erases or washes out.