I will do my best to help. First, plastic canvas or mesh comes in 4 different hole sizes. The numbers tell you how many holes per inch are on the sheet. You will find 5, 7, 10 and 14. When people refer to plastic canvas they usually mean 5 and 7. These are worked with yarn. 10 and 14 mesh are worked with embroidery thread.

When artist size is referred to it means the size of the sheet of the canvas or mesh. Artist size is usually 5 and 7 hole and is roughly 13.5 x 21.5 inches and allows you to work larger projects. I have never found 5 mesh in anything but this size sheet. The rest of the meshes come in varying standard size sheets. They are:
7 - 12 x 18
10 - 10.5 x 13.5
14 - 8.5 x 11
I hope this has helped you.

Shyane
aka Shyane