What does "napped" mean? A napped fabric is one with a "nap", meaning that the fabric is textured and will look different from different angles. Types of napped fabrics include corduroy, velvet, velveteen, Minky, faux fur, suede, and velour.
So, what does that mean when sewing? Well, the main thing to remember is pattern layout. Before you cut, you should "pet" your fabric to find out which way the nap runs. Think of how your dog or cat's coat feels when you pet them. Going from head to tail, the fur lays down nicely and it just feels "right", doesn't it? Now pet them from tail to head and see how different it is. The fur doesn't lay down at all, it sticks up, it's just not "right". That's what nap is like. And when you're cutting out a pattern from fabric with a nap, you need to pay attention to which way the nap is running. It does make laying out pattern pieces a little more complicated, just like with a one-way print. You can't flip pattern pieces over to get the most out of the fabric or your finished garment won't look right.
Another thing to keep in mind is pressing fabrics with nap. Some of them can be damaged by heat and can't be pressed, some of them need a press cloth, some of them are just fine. For this, you'll just have to take a few scraps and experiment. Look at the settings on your iron for a starting guide to what heat setting should be used. See how the fabric reacts without a press cloth. Try with the press cloth. Just remember to do this step before it's time to iron your garment/project that you're working on so it doesn't end is disaster!
When sewing fabrics with nap, I've found a walking foot is a blessing! Especially on fabrics like velvet and Minky! A walking foot will ensure that both the top and bottom layers of fabric are being fed through your machine at the exact same speed, unlike a regular foot where the bottom fabric is being fed through and the top layer is just along for the ride.
Those are my top three tips for sewing with napped fabrics. What would you add? Please comment with any other tips and tricks you've learned by sewing with napped fabric!