shirring

This is my first post- hope I know what I'm doing.I am not sure what the options mean or the poll,but here goes. My granddaughter chest measurment is 21" to shirr the whole  botice what width should I cut the botice fabric?

I think twice as much which is probably the approximate width of standard cotton prints should do it. If it's a lighter fabric you might want more than twice.

Thanks for your answer. I'll do the twice the width. I surely didn't want to shirr and entire bottice and it be too small.

I"ve always cheated--I shir a bigger piece of fabric than I should need, then after shirring, sew the seam and cut the excess--only works on really basic bodices.

I know this reply is a bit late, but I thought I would put my comments in for future readers.

When I first had a go at shirring, I got a scrap piece of fabric. It was 14 inches long. I did a few rows of shirring and then measured it. 7 Inches. Therefore my machine had a ratio 1:2. I use this ratio everytime I shirr.

As everyone's machine is different, I recommend doing this so that you always get a perfect shirr.