Stiff dresses

[Kopparbergkate]

I've just bought DD her new school dresses for the summer. They are treated with something (?) so that the fabric is so stiff I can literally stand them up on their own.

The winter uniform shirts I bought last September were the same and despite them being washed at least once a week since then, are only just now losing their stiffness.

Is there something I can soak the dresses in to soften them up a bit - the shirts were bad enough, but frankly, the dresses will look ridiculous on if they're so cardboard. I was thinking maybe dilute white vinegar or bicarbonate?

Getting dresses from somewhere else or secondhand is not an option....

Cheers in advance...

what's the fabric?

give them a wash first and see if there is a starchy sort of thing in them. IIRC starch dissolves in very hot water but not in warm, but the clothes might need cool wash.

I always wash clothes before wearing them as they are often chemically treated. Usually gets rid of the problem

I agree, a single wash usually does get rid of new-clothes stiffness but only about 30 (literally!) washes and irons did it for the shirts. Which is what I found so weird.

Care label says 35% cotton, 65% polyester, max wash temp 50. I've been washing the shirts at 40 - d'you reckon I should try 60? Don't seem to have a 50 option on my machine...

best not to wash at higher temps than the label says, some fabrics may wrinkle or bobble