Your search for "sew slip mat" revealed the following:

Tidy Tote pattern using the Sterilite Clear view Drawers, easily purchased in the US and Canada

Tidy Tote ONLINE CLASSES with bundled PDF patterns in all options and sizes

Tidy Tote pattern using the Office Works Drawer set from Australia, also from Container Store online in US and selected countries

Westalee Design Templates - Pattern 1 Table Runner & Mats

Tidy Tote pattern using the Ikea Variera shelf units, avaliable everywhere there is an IKEA

Westalee Design Templates - Pattern 3 Feather Play Cushion

Westalee Design Templates - Pattern 4 - Circles Rule

Westalee Design Templates - Pattern 2 Simple Circles