Knitted fabrics come in all weights and textures and need to be handled according to their individual characteristics. Before cutting into the fabric you should experiment a bit to see how it reacts to things like stretching the cut edge, pressing, washing and foremost how much stretch it has. The pattern you intend to use will tell you how much stretch the fabric needs as a percentage and can be from 10-25% or more.
To determine the amount of stretch, hold 10 cm of fabric across the grain and stretch it as far as it will go. If it goes to 12.5 cm then you have 25% stretch (2.5/10= 25%). Is it 2-way stretch or 4-way stretch (across the grain and with the grain like a bathing suit)?
If you plan on washing and drying the finished garment, then wash and dry the fabric before cutting. I like to do this step with all my fabrics regardless of the weave.
Press a small area of the fabric with a cool iron and steam to see how it reacts. It might stretch out completely and lose all its shape so it is better to find this out now before you try pressing seams or pleats.
Stretch out each cut edge to see if the fabric will “run” like your pantyhose. Usually, only one edge will run. If your fabric has this characteristic you must use the pattern layout designed for a “napped fabric” with the hems toward the end that does run as neck-lines and waist-lines get the most abuse when worn and are most likely to start to run.
Most patterns are designed with a “straight of grain” indicated on each piece, however, patterns for stretch fabrics will often indicate “stretch” instead. For these you will need to determine where on your fabric the greatest stretch can be obtained – across the grain or with the grain. It is important to have the grain straight on any fabric before laying out your pattern and this is true with knits as well. Put about one meter of the selvages together and hold them above your head so you can see how the fold falls, shift the layers until you can see it is straight and not pulling in one direction or the other. Pin the selvages together so they stay where you want them. Knits tend to be slippery and shift when you aren’t looking.
To hold your pattern pieces in place while cutting I prefer to use pattern weights with only a few pins holding the grain line in place. For heavy knits like fleece, cut the pattern out first so that when you cut into the fabric the pattern isn’t pulled into it and torn. For fine knits I like to leave a bit of tissue around the cutting line to help stabilize the fabric while I’m cutting. My preferred cutting tool is a wheel. It allows for more accurate cutting and prevents the fabric being pulled out of shape when lifted into scissors.
Marking knits can be done with tracing carbon and a toothed tracing wheel, although for the fine georgettes you may want to do tailor’s tacks.
My next blog will go into actually sewing on the knits.
Please feel free to contact me if you have any questions or comments.