You don’t want any unwanted surprises in production and your customer doesn’t want any unwanted surprises the first time they pull the garment out of the clean laundry basket. Creating quality clothing is all about the details. One of those details is considering fabric shrinkage. To know what shrinkage to expect and how to manage it in production and beyond, testing your fabrics for the different types of shrinkage is essential.
This is probably the type of shrinkage you think of first when talking about fabrics. Even if you don’t work in the fashion industry, you’ve most likely experienced an item of new clothing shrinking the first time you washed it. Many customers have come to expect new garments to shrink a bit, but it becomes a bigger problem if the fabric shrinks so much that the fit of the garment noticeably changes post wash.
Fabric isn’t washed and dried prior production (unless the washing is part of the print or surface treatment). This means that the shrinkage won’t happen until after the customer has bought the garment and washed it themselves. Generally, less than 5% shrinkage can be dealt with. Any more than that and it might be better to source a different fabric. At the beginning of product development, it is best to wash test your fabrics so you know exactly how much all your materials shrink in both length and width under the recommended care instructions.
Once you know how much your fabric shrinks, your patternmaker can add that extra percentage into the pattern so that post-wash and shrink, the garment comes out to the right size. Any amount of shrinkage can be added to the pattern, but if the percentage is too high, the difference between the fit of the garment when it was first tried on and purchased and how it fits after washing will be too jarring for the customer.
This is the type of shrinkage that occurs when the fabric shrinks during or after cutting. There can be several things that cause this. If the roll of fabric was spread with too much tension, the fabric can relax and snap back to its previous shape after that tension is released as the marker is cut. A tell-tale sign of table shrinkage is when your garments end up shorter but wider than your spec. The fabric was stretched in length which pulled in the width, but as it relaxes, it regains that width while the length shortens.
Depending on how many layers or plys of fabric are being spread and cut, the bottom layers of the spread can shrink more than the top layers. This is because the weight of the layers on top prevent the bottom layers from relaxing as quickly or thoroughly.
Table shrinkage is particularly something to watch for in knit fabrics. The more plys are being spread and cut at once, the more important it is to consider table shrinkage. The way to avoid this is to spread the fabric and let it rest overnight before cutting. This allows the fabric to relax on the table and return to shape before being cut. If your factory is still experiencing some table shrinkage despite letting the spread rest, you can also build in extra length to your pattern to account for this. Your factory will be able to give you details on how much is being lost to table shrinkage after the first production order, or if you’ve worked with this fabric before, you may have data on how much table shrink happened in previous production.
Multiple printing processes involve heat. That heat can cause the fabric to shrink. (Most fabrics shrink more under higher temperatures.) If your design involves printed fabric or even direct to garment printing after the garment is made, you’ll want to test the impacts of the printing process on shrinkage.
For printed fabric, it is more straightforward. Take note of the cuttable width of the fabric roll pre and post printing. You might lose a few inches of cuttable width in the fabric and this is important to note to your factory and marker maker. I’d let your patternmaker know this information as well in case your garment involves large pattern pieces that use the full width of the fabric.
If your fabric shrunk in printing, it might not shrink more when being washed and dried since it has already been subjected to heat. To know for sure, wash test a printed cut of fabric to see if wash shrinkage needs to be included or not.
For direct-to-garment printing, this is managed similarly to wash shrinkage. Based on shrinkage testing results, your patternmaker will include the needed percentage of shrinkage in the garment pattern. The only difference is that the garment will shrink before it gets to the customer instead of after.
Inconsistent Colorway Shrinkage
Similar to printing shrinkage, different colored fabrics can shrink different amounts. Expect black and dark colorways to shrink more (and feel a bit heavier) than lighter colorways. If there is a large difference in shrinkage percentage between colors, you might need to have separate patterns made for the dark and light colors. This is an extreme case, but is an option to consider. Testing your lightest and darkest colorway of each fabric will give you the information to make an informed decision on how to manage the shrinkage.
I mentioned above how heat is a big cause of shrinkage. This includes not only drying and printing fabrics, but also ironing or steaming them. If you’ve done the testing for other kinds of shrinkage and know how heat affects your fabrics, any shrinkage you include in the pattern will cover potential ironing shrinkage as well. It is still worth doing an ironing test on your unwashed fabric, though.
Remember how I said that production fabric is not washed before it is cut and sewn? The fabric that your factory will be working with is unwashed and unshrunk. Ironing or steaming is part of production, though. Most garments will be ironed or steamed along hems and edges as well as any areas of the garment that get fusible interfacing. This means that part of the garment is coming in contact with heat during production, but not necessarily the whole garment. If the fabric shrinks excessively under ironing heat, that could leave some parts of the garment inconsistently shrunken or bubbly. I don’t see this become an issue very often, but occasionally I have seen it cause problems. Trying a lower heat, block fusing, or pre-shrinking the fabric may decrease the uneven shrinkage of pressed and unpressed areas, but if that doesn’t work, you might want to find a different fabric for that design.
Fabrics can shrink in different ways and at different points in the production process. Testing for each kind of shrinkage early in development gives you the data you need to manage each step and present a quality end product to your customers.