Now I know there is really great vinyl coated fabric out there, in fact Jess of How About Orange has some fabulous vinyl fabric, but I didn't even think about that until I after I had bought a couple of yards of clear cover-the-furniture-at-your-grandmother's-house vinyl.
First observational note, do not iron the vinyl! Even with my iron on medium-low and ironing through parchment paper the heat was enough to warp it out of shape. One poor placemat has a rumpled back because I didn't have quite enough to not use all the stuff I warped.
Second observational note, you cannot pin vinyl without leaving wretched holes. If you need to hold it together bobby pins work well.
Third observational note, it is very very hard to turn under 1/4 edge on vinyl around a placemat and have it stay. I'd recommend another finishing method (I went with double-fold bias tape).
Final observational note, it doesn't like to feed too well through the sewing machine. My machine sewed through it fine, it just didn't like to feed properly.
So with those warnings out of the way, here are the placemats. I made them in sets of two; one positive and one negative. All the bases are made out of purple/pink prints and then the top layer is a green shape or the background left over when the green shape is cut out. I blanket stitched around the shapes and then covered both sides with the vinyl and bound them. This project took way longer than I thought it would, but I think they turned out nicely (except for a few glitches with the binding). The placemats were hard to photograph due to the reflective surface, but here are a few pictures.
Thanks for stopping by!