Aside from a few rides in the swing, Secora has been napping in my arms all this time. I'm not complaining. It hasn't been because she won't sleep anywhere else, it's just because I haven't really wanted to put her down yet. She's getting older though and is finally getting awake enough to benefit from some more regular naptimes and she'll probably sleep a solid stretch (rather than startling awake for a few minutes every so often) if she's in a "bed" for naps. So, we set up the pack n' play in our room and got the monitor out and I was going to start laying her down sometimes during the day. Except that the mattress is a nylon-y surface. Great for wiping off spit up, but probably not very comfortable and probably also very cold (a sure way to wake her up).
The solution to the problem? I made a flannel sheet for the mattress. It was easy to do with things I already had on hand in my sewing stash.
First step: I picked a flannel fabric scrap and held it over the pack n' play to be sure it was just a little bit bigger than the mattress (I'd say you need an inch or two on all sides)
Second step: I sewed elastic all around the edges. Voila, flannel sheet.
Sewing elastic is a little tricky if you haven't done it before. You need to stretch the elastic as you sew, which causes the fabric to gather up (if you don't, it won't stretch since your fabric can't stretch), but if you just pull on the elastic, you will pull your fabric backwards through the presser foot, so you also have to keep tension on the fabric on the backside of the machine. I had Josh take a few pictures while I was doing it and this is what we came up with
The stitch I use for doing elastic is usually a 3 step zig zag (on your machine it will look like a zig zag made up of a dotted line instead of a solid line). You could also use the stitch that looks like a regular straight stitch, but with the lines at a slight diagonal instead of being straight. Both of these stitches stretch with the fabric. The zig zag is stronger and it's also what I use to make diaper covers.
Once I ran elastic all the way around the whole square of fabric, it was ready to go on the mattress.
It looks like there are wrinkles in my fabric in places, but that's just the design, it's not really wrinkled up. You want to be sure the fabric is tight so there is no loose fabric to end up around the baby's face. I stopped at this point, but the safer bet is to also make the sheet velcro to the mattress. For that, you would need to measure out and attach velcro on the wrong side of the sheet so that the sheet attaches to the velcro spots on the mattress, and then also put velcro on the right side of the sheet so the mattress/sheet combo attach to the bottom of the pack n' play. Be aware you will need to start with a bigger square of fabric if you were going to do that.
A standard width flannel fabric is also big enough to make a sheet for a crib size mattress (I did the same thing to give Sedona a warmer sheet when she was in a toddler bed).