Thispack n play sheetfits my Combi Jazz Play Yard   “mattress” which is pretty standard and measures 36″ X 26.5″ (they’re all around 30″x40″), but the pack n play sheetis forgiving so if yours is within the general ballpark this pack n play sheet should work fine.

1.Wash, dry and cut your fabric. Add 7 inches to the length and to the width of your mattress, so i cut a piece of fabric 43″ X 33.5″.  And a piece of 3/4″ elastic 60″

1.Fold it in half lengthwise and then widthwise so it looks like this:On the outside corner, the one with no folds, cut a 3.5″ square through all the layers.
Your item now looks like this:

1.Line up the cut edges at one corner and sew them together with right sides facing:

1.Along the bottom of your pack n play sheet, fold the fabric 1/4″ to the inside and iron, then 1″ and iron, and pin in place.
Starting next to a corner, sew all the way around with a straight stitch, leaving a hole and backstitching and the beginning and end.

1.Thread your piece of 3/4″ elastic through the hole and all the way around. It helps to pin one side of it to an ironing board or some other surface and to use a safety pin to feed it through:
Pull it out and sew both sides together with a stretch stitch or a zig zag stitch.
Close the hole by sewing across the opening with a straight stitch.

You’re done!
It looks like this from the bottom:
And like this from the top:

Place your homemade pack n play sheet on the mattress.  Yay!