The question of whether you need to pre-wash fabrics before sewing with them is one that many makers struggle with. In practice, some fabrics are essential to pre-wash while others you may not need to. Pre-washing can certainly play an important role in the appearance, size and longevity of the finished product. So, let’s examine why you might want to pre-wash, which fabrics you should always wash before sewing and those which you can sew without a pre-wash.
Why You Should Always Consider Pre-Washing Fabric
Firstly, the technical explanation: the majority of fabrics, like cotton, are woven by interlacing the threads at right angles. The lengthwise grain, also known as the warp, consists of the long threads that run parallel to the selvedge throughout the length of the fabric. This direction is often referred to as the "straight grain". The crosswise grain, also referred to as the weft, includes the shorter threads that run at a right angle to the selvedge, essentially crossing from one selvedge to the other.
This is important in the context of pre-washing as the fabric could shrink more on the warp than the weft and vice versa, particularly if the fabric has been stretched to fit on the fabric roll. We all have T shirts which, once washed, no longer line up on the seams – well, that’s the reason why. This is particularly true of knit fabrics like jersey. So, pre-washing should help to re-align the grain if it has been stretched or distorted.
The Importance of Pre-Washing:
Many fibres shrink when washed for the first time, so this is one of the most important reasons to pre-wash your fabric. In addition, some fabrics may “bleed” their excess dye which wasn’t entirely removed during the manufacturing process. Finally, one advantage of pre-washing is to make the fabric softer and therefore easier to work with. With some fabrics, pre-washing may also reveal any fabric defects before you start your project.
Fabrics You Should Always Pre-Wash:
Some fabrics are sold already pre-washed which makes life very simple. Check out our pre-washed collection for a selection of pre-washed linen, denim and cotton.
Here are the fabrics you should always pre-wash unless the manufacturer states otherwise:
Batik Fabric
These beautiful hand-dyed fabrics are known for their vibrant colours, but they can also bleed significantly. As batik is made through a manual waxing and dyeing process, you should always pre-wash to remove excess dye and to test for dye fastness. Check out our previous blog on tips for sewing with batik.
Cotton Fabric
Cotton is a natural fibre that may shrink when washed. Pre-washing cotton fabric helps to pre-shrink it, ensuring that the finished sewing project will maintain its size and shape even after washing.
Double Gauze
With its distinctive crinkly texture, it’s always a good idea to pre-wash double gauze as without ironing, it will almost certainly shrink from washing.
Linen:
Like cotton, linen is a natural fibre made from flax that can shrink significantly. Pre-washing will help you get rid of any shrinkage before you start your sewing project. Or look for washed linen fabrics like our linen handle which have been pre-washed for you.
Denim:
Denim, particularly darker indigo or black shades, can have a lot of excess dye that could bleed onto other fabrics. Pre-washing helps to remove this excess dye and softens the fabric, making it easier to sew. However, if you can buy stonewashed denim, this will have been pre-washed for you. Read our blog on sewing with denim for more top tips.
Flannel:
Flannel is known for its shrinkage and should always be pre-washed. Pre-washing flannel also helps to enhance its softness, making it even more comfortable for projects like pyjamas or quilts.
Knit Fabrics like Jersey or Ponte
Knit fabrics often shrink when washed and can shrink differently to woven fabrics so it’s always safer to pre-wash. Once pre-washed be sure to read our guide to sewing with knit fabrics.
Seersucker
Seersucker’s trademark puckered effect is created by weaving threads together to create the crinkled look. It can shrink slightly after the first wash which refreshes the puckered effect; we therefore recommend always pre-washing seersucker before sewing.
Viscose
Viscose is made from cellulose or wood pulp and can behave like a natural fibre in terms of shrinkage so it’s best to pre-wash gently before sewing. Pre-washing viscose also helps to remove the chemicals employed during production.
Voile
Voile is such a delicate lightweight cotton that it’s a good idea to pre-wash in case of shrinkage. It is best to put delicate fabrics like voile, which might fray in a laundry bag before washing.
Fabrics You Can Skip Pre-Washing
While pre-washing is an essential step for many fabrics, there are a few exceptions to the rule. These are typically synthetic fabrics that are less prone to shrinkage and colour bleeding. Others like silk, velvet and wool are almost always dry clean only.
Polyester:
As a synthetic material, polyester is generally resistant to shrinkage and colour bleeding, making pre-washing unnecessary. However, if your polyester fabric is mixed with a natural fibre like cotton, you may still want to pre-wash it.
Nylon:
This synthetic fabric is also resistant to shrinkage. While it can be pre-washed if you prefer, it's generally not required.
Spandex:
Known for its elasticity, spandex is another fabric that doesn't typically need to be pre-washed. However, if it's blended with a fabric that does require pre-washing, you'll want to treat it as if it does.
Wool and Wool Blends:
Wool fabrics and wool blends are often dry clean only, so pre-washing in water can damage these fabrics. Always check the care label before washing wool. Boiled wool has already been pre-washed so again, you can sew with it straight away.
Silk:
Pure silk is a delicate fabric that usually requires special care. Most silk items are dry clean only, and pre-washing at home can lead to permanent damage or colour loss.
Velvet:
Velvet is one of those fabrics that is ruined by washing so is excluded from the pre-wash list. Always spot clean or dry clean and read our handy guide to sewing with velvet.
Remember, while these fabrics generally don't require pre-washing, it's always a good idea to check the care instructions that come with your fabric. Each fabric is unique and may have specific care requirements to keep it looking its best.
How to Properly Pre-Wash Your Fabrics:
The general rule of thumb is that you should wash your fabric exactly as you would wash your finished piece. Here is a step-by-step guide on pre-washing.
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Separate Fabrics: Just like your regular laundry, sort your fabrics by colour to prevent any colour bleeding. Also, try to wash similar fabric types together. It’s probably safer to pre-wash a fabric on its own to prevent any damage or colour transfer.
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Temperature Settings: As a general rule, wash your fabrics in the same temperature water you plan on using for the finished product. We would recommend temperatures of 30 degrees or lower. For most fabrics, a warm or cold wash and cool rinse is a safe bet. However, always check the care instructions of your fabric.
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Choose the Right Detergent: Use a mild, colour-safe non-bio detergent to protect your fabric. Avoid using any bleach or fabric softeners as they can alter the fabric's colour and texture.
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Washing: Place your fabric in the washing machine, ensuring it's not too crowded. This will allow the fabric to move freely and get thoroughly cleaned. Choose a delicate wash machine setting if appropriate for your fabric. Or you can hand wash your fabric but take care not to wring the fabric too tightly to remove the excess water.
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Drying: Once washed, it is nearly always safe to line dry your fabric, except for knit fabrics where the hanging may result in unwanted stretch. You may also be able to tumble dry on a low setting, unless the care instructions suggest otherwise and if in doubt, do not risk it. Many fabrics will be better air-dried to prevent shrinkage or distortion.
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Ironing: After drying, iron your fabric while it's still slightly damp. This will help remove any wrinkles and make it easier to work with. Ensure to set your iron at the appropriate temperature for the fabric type.
Remember, the key to pre-washing is treating your fabric as you would treat your finished product. This ensures that any changes in size, colour, or texture happen before you start sewing, rather than after.
In conclusion, knowing whether to pre-wash a fabric before sewing will help guarantee a professional finish on your makes. Wash as you would your finished garment unless it is a dry clean only fabric like velvet or wool.
If you are unsure, then feel free to email us on howdy@fabricsgalore.co.uk or call our fabric shop in London and one of the friendly team will be able to help.