fabric
 

Hello Quilters............since I'm green when it comes to fabric.........how do you tell the difference between 100% cotton, cotton/poly blends and poly(broadcloth)......I've been given over six large bags full from someone who can no longer sew........

I use the burn test. Take a small piece of the fabric in question and burn it...cotton turns to ashes, poly/cotton and blends will melt into a little ball. How fun to get a bunch of free fabric.

Also, don't be afraid to use cotton/poly blends in a quilt. If you like the feel and look of the fabric, use it.

I test with my iron. Poly or blends give off a distinct odor when you iron them, but be sure to lower the temp of the iron when doing this because if the iron is too hot it will burn poly.

Cari

When testing for content, you can put a swatch in bleach and if it dissolves it is wool. If you get ashes and little beads, it is a cotton/poly blend. Hold the fabric up to the light. If you can see through it, it is a poor quality cotton. After a while, you'll be able to tell a quality cotton by feel.

I use the burn test.

I light a candle and get an ash tray handy. Also a glass of water nearby - just in case. It is better to do this outside - the burned smell can linger inside the house.

I cut a snibble of fabric - about 1/4 inch by 1 inch is plenty large enough - and hold it with tweezers into the flame until it ignites. Poly (and other petroleum based fibers) will burn with black smoke and usually leaves a hard ash. The residue stays hot longer than the residue from cotton. Cotton leaves a soft ash. I put the burned fabric in the ashtray.

I can't tell rayon from cotton, though. Wool smells like burning feathers.

I will occasionally get a cotton/poly blend that I think is 100% cotton - but it is a blend.

I am not one who likes to prewash my fabrics - BUT - if you are not sure of your fabric content, I would prewash so they all shrink or don't shrink before you assemble the top. If you were making an heirloom or for some shows, you should be using 100% cotton. But, there is absolutely no problem with mixing whatever fabrics you have. Think about the old crazy quilts with cotton, denim, velvet, feed sacks, whatever. The important thing is that you like the fabric! It is your quilt and you get to make it whatever way you want!!! THERE ARE NO QUILT POLICE!

The biggest lesson I have learned when using cotton/poly pieces in a quilt is to cut pieces a little larger than they need to be. I find the fabric "shrinks" once cut, and it's straight grain does not have even the minimal stretchiness of all cotton.

it should all work in quilts

Observations:

When you cut 100% poly fabric, the threads on the cut edge are straight, no bend to them. The fabric usually doesn't wrinkle. I think it is harder to piece with, so generally don't use it. Sometimes it pills. Generally, it seems to ignore the pressing to the dark side thing.

In my opinion, it doesn't quilt up nearly as well as a cotton or a good poly cotton. As someone already suggested, a hot iron will tell you whether a fabric is poly or cotton. It melts poly. The melt stays on your iron, so I suggest that you put a piece of freezer paper or aluminum foil over the test fabric before you press. Alternatively, You could cut off a small piece of the fabric, place it in a bowl and light it with a match. The residue is not ashy like cotton, but looks like a small twisted piece of black plastic. Best to do that near a sink so you can douse the fabric piece quickly if you need to. (To date, I have never needed to!)

Cotton, on the other hand, the threads are softer, and will feel like a cotton thread, and definitely will bend and curve. It pieces more smoothly, and obeys the iron.

Poly/cotton usually does not wrinkle like a 100% cotton fabric. It is less likely to obey the iron than 100% cotton, but generally can be pressed into submission. I have never flame or iron tested poly cotton. The threads at the cut end are generally straighter and hold their shape more than 100% cotton, but have more bend than 100% poly.

There are different percentages of poly/cotton, 70/30, 60/40 40/60 and so on, so you really have to test piece the poly/cottons to see if they will work like you want when piecing with it. I use this occasionally as backing, but generally not in when piecing a top.

Because of the melt factor, NEVER use poly or poly/cotton in things like pot holders, table toppers, etc. That is also true for polyester or poly/cotton batting.