HI..
Not sure but I think you could wash again and use a fabric softener. That should soften them up. Glad to have the idea though. My Mom is wanting a new duvet for her down comforter and she put it on MY list of to dos. Hadn't thought of using sheets but makes great sense. Now if we can find some she likes....LOL.
Murphy

I doubt fabric softener will work - this is a surface issue - it feels like something has been painted on. I am quite surprised that something that carries the Martha Stewart name (and price tag although I got them at a discount price - maybe there's a reason for that?) would feel so - crappy.

Try washing in plain water with a couple of cups of vinegar.

It's the coating that lets the sheet-making machinery work better. Not permanent, but it can take a couple of washings to get rid of.

Well I have washed the sheets a couple of times in hot water - the last wash I used just white vinegar - about 2 cups (no detergent), let the machine agitate and then soak for a bit. After they came out of the dyer they were significantly nicer, the "hand" is closer to what I am looking for! It's funny but one sheet is solid and I am happy with the feel of that one, but the other is printed and had the more "plasticy" feel, now greatly reduced. I am going to try again with the vinegar, thanks for the suggestion Lazygardens!