Spring Clips + Screws - Holds back or canvas in picture frame - 3 Sizes FREE p+p | eBay
888 Corp Extra Heavy Duty Canvas Offset Clips with Screws (1/2") Pack of 10 : Amazon.co.uk: DIY & Tools
Offset Canvas Clips For Picture Framing Starters Package. Includes (20) of each 1/8 1/4 3/8 1/2 3/4 1. Included is 120 pieces #6 X 3/8 pan-head screws. by Gittels Art Supply : Amazon.co.uk: Garden