In today’s blog I will explain how to prepare the fabric before cutting it, but before I will explain why some people prefer to wash the fabrics in the washing machine before cutting it.
Here it will depend on certain factors, such as whether what you are sewing is for you or is to sell but these are the most common reasons:
Dirt
In this case it will depend on where you bought the fabric but it could be dusty, if cleaning was not their strong point, or you may see traces of grease in the fabric.
Remains of dying and chemicals
When manufacturing fabrics, the most common dyes use quite aggressive chemicals plus they use other chemicals to give the fabric properties (like a shine or to have a silkier touch).
Certain people can suffer allergies to these chemicals or the dyes can stain skin (have you ever had blue legs after wearing new jeans in the rain?). People also wash fabrics where they are using two different colored fabrics to try to prevent the colors from mixing.
Thread tension
As I explained in the previous blog, fabrics are made of interwoven threads. When these threads are being made into fabric, they are put under a lot of pressure and then when you wash the fabric, the threads “relax”.
Shrinkage
Now we move on to the last and most important reason from a patternmaker’s point of view, fabrics shrink.
We have a general rule in the industry that up to 5% shrinkage is acceptable. Obviously this will change according to the type of fabric.
Have you ever seen that collar shirt have “bubbles”? This may be because the interfacing is of poor quality or the fabric has shrunk but the interfacing retains their original size.
Just remember, what I am talking about here is preparing the fabric for cutting and sewing. I am not talking about washing tests, that is something else.
The correct way to prepare the fabric
I personally don’t recommend washing the fabric unless you have allergy problems. The most important thing I want you to get out of this post is that you have to pre-shrink fabrics before cutting them.
Pre-shrink
It is very important that you pre-shrink your fabrics, because if not, once you are making garments and iron them, they could shrink and the pattern will deform.
It is very easy to do. Just use a steam iron (first test how the fabric reacts in a corner) and then iron the fabric from top to bottom or from right to left with steam. If it is a very delicate fabric, just apply the steam but do not touch the fabric with the iron. Never do it diagonally! If you do, you will probably distort the thread.
What the biggest companies do.
When a company sends their patterns to be made abroad and they request many units, the usual thing that they do is to do a shrink test. This will show the shrinkage percent on vertical and horizontal.
Once they have the result, they will modify the patterns for that fabric. Then a very large machine will cut it and then they will shrink the fabric to the size their want.
This was very helpful, thank you very much.
No problem at all! I am so glad you like it!
Hi, could you help me to understand this sentence: “Once they have the result, they will modify the patterns for that fabric. Then a very large machine will cut it and then they will shrink the fabric to the size their want” – do you mean that each piece of pattern is ironed? I was always wondering how the manufacturers prepare clotes from viscose , without washing it. It was only one time I sewed a viscose garment without pre-washing and after first wash it was 1 size less.
Hi Dorota, this will depend on the company. The most normal thing to do is to cut the pattern (with the % of shrinking) and they sew it and while they sew they will press it and that will make it to the right size.
I have 4 1/2 yards of cotton fabric Seems to big to wash and iron out. What if I cut the fabric 2 sizes larger and then wash and iron?