Boards
Never ever buy bed sheets from Ikea
Just washed mine then and tried to put them back on when I realised that the opening were you put the duvet into does not extend across the whole width of the bedsheet.
Now the professional bedmakers of you will realise that this meant I couldn't do the shakey-thing (it's an industry term) to get my duvet in. Nigh on 20 minutes later, and what I think may be a back strain, I have finally made my bed.
I'm not sure if this cleanliness lark is worth the hassle.