I have several types of fabric that I love to work with...during the summer my hands down favorite is linen...and during the winter it's wool crepe. The things that I love about wool crepe are ~ that the fibers take dye so well. This fabric can be found in vibrant oranges, reds and deep purples or pretty pastels. The second thing I love is the hand - there is such a wonderful drape to this fabric especially when you purchase a high quality wool crepe. The third thing is the way the fabric holds a stitch...when you are sewing the fabric it allows the stitches to sink into the fabric...they are enfolded into the garment without any effort on your part...This fabric is just a joy to sew.
Wool crepe just has one drawback! You absolutely positively must pre-wash, pre-treat, pre-something the length that you work with because if you don't your finished garment will shrink. It might not shrink much the first time you clean it but it will definitely shrink in degrees over its lifespan. And it could end up being a very short lifespan if you don't pretreat it.
Now there are four methods generally used to pretreat this fabric:
1. The London Shrink Method
This method involves getting your entire piece wet, well damp and then rolling it up between two sheets and letting it dry naturally and checking it over time to see if its dry, rerolling it, maybe dampening it again...can I state again that its very involved and you need a lot of space if you have a lengthy piece!
Probably the easiest and most costliest method...you take it to the dry cleaners and they steam press your fabric.
3. Washing and Drying
Let me caution you here that whenever you wash & dry a length of wool crepe not only will you have shrinkage but you may also have some felting (melding of the fibers). So unless your intent is to manipulate the fibers, I would not suggest this as a pretreatment method. However, if manipulation is what you are after, you get the best results by washing and drying the fabric multiple times (at least 3 in my experience).
4. Steam the heck out of it
This is my preferred method of pretreatment cause I'm too lazy to London Shrink and to time challenged to lug it to the dry cleaners. Even though I have a great dry cleaners that picks up and delivers my clothing but that is another post! The steps I use when doing "the steam the heck out of it method" are pretty simple.
First - you need a good size bowl of water and two cotton batiste press cloths. I like two because one is always in the damp water ready to be used. And my cloths are usually 45" wide and about 12-14" long. These dimensions are good for me because they cover more of the fabric when pressing.
Two - you need a good steam iron and alot of water for your iron especially if you are pressing a long length of fabric.
Three - I like to cover the floor around my ironing board with an old sheet. This way my fabric can hit the floor and I don't have to worry about dirt/dust etc.
Then I use the highest setting on my iron which I think is the silk setting. Don't worry you won't burn or scorch the fabric because the press cloth will be between the fabric and the iron. I wring out one of the press cloths and lay it flat on the fabric. Next I "press" the press cloth until it is dry creating a lot of steam.
Press not iron - picking the iron up and placing it down in the next position, not gliding it from place to place. There should be clouds of steam arising around you when you are doing this. When the press cloth is relatively dry, I remove it and place it back in the bowl of water.
This next step is real important, I do not move the fabric for at least 2 minutes to allow it to dry and all of the steam to pass through the fabric. Only after that do I move that section and start the process all over again in a new section. Now if you have a vacuum pressing table and a steam generator iron this process goes a lot faster...I have the steam generator iron but not the pressing table so my 2 minute rule is hard and fast!
This is a very time-consuming process...yes, I know I stated earlier that I'm lazy, however, I love this process. I usually pre-treat 2 or 3 pieces at one time because of the time factor and I want to have them needle ready when I'm inspired to use the fabric for a garment. I usually do this with the TV on and a good movie going. And I use ALOT of steam!!!!
I have been using this method for pretreating wool crepe for years and I have never had a garment shrink after being dry cleaned. So this is what I will be doing tomorrow morning...pretreating a few lengths of wool crepe in preparation for making a new dress.