Oilcloth is actually best. The vinyl from the sheet package does not have a fabric backing, so it loses a great deal of flexibility and is therefore much more prone to rips, tears, and cracks. You can probably still get away with using it (heck, why not? reusing materials is always worth a try!), but it would be wise to use the longest stitch length you reasonably can. This will avoid perforating the vinyl, which would make it as easy to tear as a check from a checkbook.