If you're new to making muslins, all you need to know is this: a muslin is a test version of your garment. You can make it in unbleached cotton (called muslin), but the best rule of thumb is to make it in a fabric of similar weight to your fashion fabric. Muslin generally comes in three weights: light, medium, and heavy. I'm pretty sure I'll be making my Lady Grey in this heavy tweed, so I'm going to opt for heavy tailor's weight muslin.
There's certainly no need for your muslin to be made of actual muslin, though. I've made muslins out of old curtains, and sheets from Goodwill are a reader favorite. Again, just make sure that your muslin fabric is of a similar weight to your fashion fabric. This will help you see how the coat will drape. As Sarai—the pattern's designer—pointed out, the peplum of this coat can look anywhere from subtle to very dramatic, depending on the weight of fabric you use.
Here's your supply list for your muslin:
- Muslin (or equivalent) in same yardage required for shell of coat (Note: we won't actually be making all of the pattern pieces in the muslin stage—facings and pockets will be omitted—but it doesn't hurt to have a little extra.) You can buy muslin at any fabric store.
- Thread in two different colors; make sure they both show up well on your muslin fabric. The first will be for thread-tracing your seamlines by machine, and the second is for actually assembling your muslin. This is a good opportunity to use up weird odds and ends of thread that you have lying about.
- Tracing Paper. I like the big pieces of waxy paper, but you can also use the regular stuff you find at Joann, like Dritz or Clover.
- Serrated Tracing Wheel.
P.S. The Sew-Along Flickr Pool is up! Make sure you join up. And hey, why not introduce yourself with a pic of your fabric choices?