how do I mend a tear in a silk/poly shirt?

The best thing to do is get something called Bondaweb, sometimes called Wundaweb. It is iron on and comes with either one or both sides adhesive - you need the one that is single sided. You need to pin the tear so it sits edge to edge and then really carefully iron the bondaweb onto the reverse side of the fabric. make sure that you cut it with about 1cm spare each side of the tear, as otherwise it may show through on the right side. Once it's bonded to the fabric, it's hard to get off, so be carfeul and make sure the tear is a straight beore you fix it!

SamB
November 2007