I used all reproduction vintage fabrics for mine--many of which were purchased from ReproDepot--although you could use real vintage fabrics or any other patterned fabrics that appeal. You could also use scraps you have laying around, waiting to find their purpose in life. And I designed a vintage-look backing with an elephant graphic that says, Don't forget--because that is the point of a game like this--to remember and not forget where you saw the match to that one piece?
Of course, you know I had to make this into a tutorial for you. You can download that here:
DOWNLOAD MEMORY GAME TUTORIAL
And if you wanted to give it as a gift, you could make a little drawstring bag to put all the pieces in, appliqueing a square or two of the fabric on the front--or you could cover a little cigar box in some sort of decorative paper and stack the pieces inside.
I do plan to put a couple of sets of these in my Etsy shop--probably tomorrow. Watch for that, if you care.