DecoBob Prewound Bobbins Class 15 12ct Black White Cream Grey. Class 15 Decobob prewound bobbins. 80wt cottonized soft polyester. Basic colors: White, Black, Creme, Grey. Matte finished to blend with most fabric. 12 bobbins in package. Class 15: 135 yds per bobbin. DecoBob is recommended as a general bobbin thread for all types of professional work, machine embroidery and thread painting in particular. The thread is tightly wound on high quality AS bobbins with are re-usable. Unlike most other prewound bobbins, DecoBob prewound is free of any chemical adhesive to ensure unhindered delivery of the thread. This also avoids the build up of undesired residue in both the bobbin case and the machine. CHK-DBP15BASIC