I really don't know since I haven't made it, but stockinette stitches are also narrower. Try this to see how it works for you. Make 2 swatches, one in garter AND one in stockinette. CO the same number of stitches and and do the same number of rows, but make them big enough to be a useful measure. It's important to use the same number of stitches and rows as you would in a pattern. Then you can see how the stockinette looks compared to the garter.