The warehouse has been flooded with new shipments the past few weeks, and part of the goodness is some snuggly soft,
polka dot flannels
All of these flannels remind me of those beloved flannel pajamas I had when I was a kid. You remember those, don't you? The set that was a bit too large when you first tried it on, then fit just right after 2 or 3 washings, and then, without you realizing it, was too short in the arms and legs, as if you had a sudden, overnight growth spurt? Well, whether or not you had that growth spurt, chances are good that you also fell victim to progressive shrinkage - common to flannel fabrics.
So, what is progressive shrinkage, and what can we do about it? Progressive shrinkage is quite similar to felting in wool fibers - loosely woven fabrics or fabrics woven with relatively long staple fibers are subject to greater fiber movement when agitated in water. So, even in cellulosic fibers (plant-based fibers like cotton, linen, hemp, etc.), progressive shrinkage can occur in certain weaves or fabrics with particular fiber types. Cotton flannel (or flannelette) is usually a simple or twill weave fabric made with short staple fibers. After it is woven, the surface of the fabric is "napped" on one or both sides - a process that pulls the ends of those short fibers from the weave with stiff bristle brushes. This results in a soft, brushed fabric that is a bit fuzzy to the touch. The loose weave and the napped surface of the fabric allow the fibers to shift and become more dense when they are agitated in the washing machine. The fibers will continue to become more densely packed in the weave, wash after wash, until they are stable and cozy with their neighbors... and there you have it: progressive shrinkage.
But, don't give up on flannels just yet! Now that you know how this happens, you can be proactive and successful when sewing with flannel. Simply pre-wash all of your flannel fabrics in hot water 2-3 times before sewing. A hot water wash will help to accelerate the shrinkage, and most shrinkage occurs in the first few washings. If you are combining flannel fabric with non-flannels in a project (flannels make great quilt backs!), this is especially important. Otherwise, the areas with flannel will shrink at a much faster rate than the non-flannels, making your project pucker or become misshapen. Be especially aware of potential shrinkage when making garments. If you know your fabric is going to shrink, always pre-wash before cutting your pattern pieces so that you don't end up with something too small. Even though pajamas can start out loose fitting, you don't want to end up with capri pants during those cold, winter months!
Have a question about fabric? Let us know, and we'll feature it in our Fabric 101 series. If we don't know the answer, we'll find someone who does!