I got 2 sets (3 piece set including bumper, sheet and comforter). Usually bumper may not be 100% cotton, but the sheet should be (and better be) 100% cotton. I got two more sheets since that would be changed frequently. There are 4-piece or even 6-piece, 10-piece sets out there for more bucks. But in my opinion, only bumper, comforter and sheet are the absolute necessary. So if you are on budget, get the 3-piece set. FYR, here are the two I got. http://www.target.com/p/Tiddliwinks-Batik-Butterfly-3pc-Baby-Be http://www.target.com/p/Circo-Bedding-Set-Neutral-3-pc/-/A-1353