Tutorial, part 5 - Stay Tape

Reinforce the top of the trousers with stay tape to prevent them from stretching undesirably at the waist. 

You can use some standard stay tape like that commonly used in jackets' roll lines, pocket edges, etc. - it's basically a kind of twill tape. This stuff is really handy to have around for many other sewing/tailoring purposes, as well! 

I got 144 yards of it from Wawak for less than $13.

Or, if you prefer something a bit thinner (less bulk), you should be able to find some thin, webbed, nylon stay tape at your local fabric store (or here's another link to Wawak), which will also work well:

As far as we're aware, you can't go wrong with either kind. 

Whichever kind you chose, sew a length of it to the wrong side of the trousers around the top, with top edges flush:

Cotton twill stay tape

Nylon stay tape

PREVIOUS: Tutorial, part 4 - Front to Back

For TROUSERS, continue to the next step. 

For OVERALLS, skip to step 7.