Sewing - black and gray picnic placemat with a zippered pocket

I made another picnic placemat from precut pieces from my stash. The dimension worked out quite well.  I sewed the back to the front right sides together and left the zipper open a bit so I could turn it over.  I top stitched to the left of the zipper to create the pocket and then all the way around the perimeter.  I did forget to put in the ties so had to undo the seam and insert them and restitch.  I was aiming for about  12" x 18" but with the size of the precut pieces I was a bit off on some of them.  They will work quite well regardless with enough room for a place and a pocket for utensils and a napkin.     Therese