Understanding Knit Fabric

Why Understanding Knit Fabric Bases Matters

Even when fibre content looks the same, structure changes everything.

Two fabrics can both say: 95% cotton / 5% lycra but behave completely differently because one is rib knit and one is French Terry.

That’s why checking:

• Stretch percentage

• Recovery

• Weight

• Structure

  are so important before cutting into your fabric.

If you’re unsure about stretch percentage, look out for our upcoming blog on how to calculate fabric stretch percentage. 

When Can You Substitute One for Another?

This is our opinion, based on how we’ve used our fabrics. This isn’t to say it will always work, and it may take some trial and error, and it will also depend on how your pattern is drafted. 

Can you use rib instead of cotton lycra?

Sometimes, but expect:

• More cling

• More stretch

• A firmer fit due to the recovery

You may need to trim down cuffs or adjust neckbands to use rib if they’ve ben drafted to use cotton lycra. 

Can you use French terry instead of cotton lycra?

Usually, but only if:

• The pattern allows lower stretch

• The garment is relaxed fit

French terry won’t work well for fitted tees or leggings, but you could size up and have a baggier fitting tee that’s a little thicker than standard. For leggings or other bottoms, as long as you have a waistband that will hold them up (using something like elastic or CL) and they’re not too tight in the legs, you should be able to make it work if that’s all you have. 

Can you use cotton lycra instead of rib for cuffs?

Sometimes! Cotton lycra doesn’t have the same “snap back” structure rib does, so cuffs may stretch out over time, or feel tighter to get over the hands or feet. That said though, we use it often and find that if you cut them just a tiny smidge bigger then it works ok!

Knit Fabric Comparison Chart

To make fabric choices easier, we created a simple comparison chart that includes:

• Stretch type

• Typical stretch range

• Recovery notes

• Common uses

• Weight range

Print it out and keep it near your cutting table for quick reference when planning projects, or use it digitally, your choice!

👉 See the knit fabric comparison chart here.

Sewing with 3am Threads Knits

Hopefully this helps you understanding knit fabrics, but if you’re browsing our preorder pages and are unsure which base to pick that suits your pattern:

• Check the Fabric bases page for information on width of fabric and composition

• Use the knit fabric comparison guide 

• Or, reach out through email or on our instagram page! We’re always happy to help.

Holly and Jen