Fabric 101: Progressive Shrinkage
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!
Tags: flannel, progressive shrinkage
September 7th, 2008 at 9:24 am
Thank you for that information on progressive shrinkage. I love your products and am always looking through and doing my wish list. Also - I love it that you include 2 pieces of Japanese candy with each order. My children and I love them! Thank you for providing such great fabrics.
September 7th, 2008 at 11:37 pm
Interesting stuff for us fabric junkies. Thanks for sharing!
September 9th, 2008 at 6:44 pm
well this makes sense. here i thought i was just eating to much!! hehehe
October 21st, 2008 at 9:02 am
When you say hot wash do you mean 60 degrees or 95 degrees - thanks
October 21st, 2008 at 11:47 am
Hi Woody! The temperatures on your washing machine are largely dependent on your water heater settings. Hot water can be 130F or above, warm is between 90 and 110F, and cold is 60-80F. But, you’ll want to check your water heater settings to see if you have set a maximum temperature. It is often recommended that the maximum temperature be lowered to save energy. Also, the distance between your water heater and washing machine will affect the temperature; the longer the distance, the more the water cools before reaching your machine. If you need a precise measurement of the temperatures on your machine, use a thermometer to measure each temperature setting as the machine fills. Good luck!
October 22nd, 2008 at 2:32 am
sorry i was talking centigrade forgetting that in the US it is different. No worries I will give it a go later today. I have a front loader machine and it is cold water fill and heats to the correct temperature.
October 24th, 2008 at 12:18 am
Fascinating info for consumers and lovers of flannel. Living in the deep South (TN) we don’t get to wear our flannel as often as I’d like, but this is great info to know! I’ll be sure to pass it on to many others who suffer “shrinkage” issues and we all thank you very much!
November 4th, 2008 at 8:10 am
[...] I had some pink spotty flannel which I tried to shrink as much as possible as per a post on the Superbuzzy blog. The pattern came together really quickly, but it would have been quicker and easier if I had a [...]
November 14th, 2008 at 12:04 am
Is there a percentage I should add to my total yardage to allow for the shrinkage? I’ve calculated that I need 44.75 yards to make 17prs of pj pants. I’d hate to prewash the fabric and end up short.
Thanks!
November 14th, 2008 at 12:49 pm
Hmmmm - that’s tough to say, since the amount of shrinkage can vary depending on the quality of the fibers and the density of the weave. Since you’ve got a major sewing production going, I would suggest completing one pair as your sample before you purchase all of the yardage. That way, you’ll have a shrinkage gauge for the rest of the pjs, and you can estimate your yardage even more accurately. Good luck!
September 10th, 2009 at 6:13 pm
Hi! I was surfing and found your blog post… nice! I love your blog.
Cheers! Sandra. R.