I have about 15 framed sheets so far. I go to Hobby Lobby and get a 22x28 (inches) Exhibition (Frame type/design line/brand) frame. This will leave about 1/2" of space on the top and bottom of the sheet, but fits the sides perfectly and the slight bi of space above and below just look like part of the sheet itself.. It's a satin black frame, flat, and about 1.5" wide. It's elegant looking. They are $44.99 each, but if you use the Hobby Lobby app, you can apply the 40% off coupon to it. Last week, all of their frames were 50% off, so I picked up a half dozen for my next few sheets. They look great, are inexpensive, and I can get more, so my collection has a consistent, unifying look. I have mine on the walls on my stairwell that goes down to my game room and theater. I get a lot of compliments on them.
I recommend them highly.