So here is the finished project.
1- I squared the piece of material I embroidered on to 12x12 inches (well at least I tried) and pressed it.
2- Measured and cut the strips of spider material to border the white. The 2 long strips were 16x4 inches and the 2 short were 12x4 inches.
3-I then pinned the 12 inch pieces to the sides and stitched them down.
4- I then pinned and stitched the 16 inch pieces to the top and bottom.
5- Then I pressed the whole front piece.
6- I then laid the front against another scrap I had of the white fabric. It needed to be about 3 inches wider than the front. and trimmed it to fit.
7- Cut the back piece about 2 inches off center, this will over lap. Hem the edges of where you just cut about 1/4-1/2 inch.
8- Line up the unsewn edge to the edge of the front. Stitch the side right sides together. Do the other side. If you lay it out flat you should have white pieces on the side.
9-Fold over sides, they should overlap just off center of the back. Now you will pin and stitch across the top and bottom. Trim your threads and any extra overhanging pieces.
10- Turn it right side out. And insert your pillow.
I was so worried about it not being big enough to fit over the pillow that it ended up being a little big but that is an easy fix.