For quality sheet fabric - I prefer a really good, firmly woven muslin - try your local quilt shop if you have one. They tend to carry both muslins and percales in both white and cream, for use as quilt backings. Of course, "you gets what you pays for", the good ones are not cheap.
I just changed the sheets on our bed, and now I'm resting. Between the sheets - which weigh a ton - and the super-thick mattress, this is work! Why is it that I never get the bottom sheet on the right corner at first? I keep thinking I should mark them, but by the time I wrestle everything onto that monster-mattress, I just need to sit down and get a drink of some kind. The sheets are either 800 or 1200 thread count, depending on which set I use, and I don't iron them. I figure the bottom is so taut, it doesn't matter, and the top is covered by blanket and quilt, and I don't care. ;-) It's all compounded by the mattress, which puts me in nose-bleed country by the time I climb up into the danged thing. I seriously considered getting steps.
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