Since we bought new beds and mattresses for everyone (in the last 2 years) we've really struggled to find any fitted sheets that are deep enough to actually fit on them. Even some of the supposedly 'extra deep' sheets we've bought are barely deep enough when bought (just reaching the underside of the mattress) and then shrink as soon as they're washed (so they don't stay on).
None of them are especially fancy mattresses, and they're standard UK sized singles (for the kids) and a king-size (for us). DS2's mattress isn't even particularly deep. DS1's and our mattresses are deeper, but not ludicrously so. They're roughly the same as all the other mattress in the shops.
So does anyone have any recommendations for fitted sheets that actually fit a mattress? I don't want flat sheets because they're harder to put on (I have arthritis everywhere and want something simple) and inevitably go all wrinkly). I just want a fitted sheet that actually fits our mattresses.