sarahrachel

you know, I don't think I've ever pre-washed any of my fabric, and neither has my mom which is where most of my fabric comes from. I've never had an issue with it bleeding and I don't know why. Would it have anything to do with the fact that we always wash our quilts in cold water?

Grama Lehr

Amen!!

BellaBoo

If I think a fabric will bleed I go in the restroom of the shop/store and wet a paper towel with hot water. I take to the fabric and on the very end by the selvage I rub a tiny spot. If any color gets on the wet paper towel I don't buy it. I have saved myself lots of frustration, even if I love the fabric, I find something else. Some shop owners don't mind at all to try the test others say NO the fabric is quilt shop quality and won't bleed. Yeah right.

kittycats

I think color catchers are good, but that some have been washed, in cold water, several times and still had color on the catcher.

greenini

Since most of my fabric is of uncertain parentage (thrift stores, yard sales, etc) I have always washed everything. Latley I've been picking up some LQS fabric on sale and had thought I could skip the pre-washing, but guess not!

craftybear

thanks

MsEithne

I agree with you.

I'm a hand dyer and I always laugh a little when I see the recommendations to "set" dye by washing cotton fabric with salt or vinegar.

Salt is sometimes used in the dyeing process to chemically drive the fibre reactive dye molecules away from the water molecules (with which they will happily bond and thus be wasted) and towards the receptor sites on the cotton fibres. Once whichever chemical that creates an alkaline environment has been removed, adding salt is not going to get stray dye particles to do anything.

Plus, the amounts of salt usually recommended are pitifully inadequate even if the fabric were prepared to receive more dye molecules. Quantities required vary but are usually around one cup of salt per gallon of water. That would mean around 20 cups of salt for a washing machine load!

Vinegar won't work because cotton is not dyed with acid dyes. Being exposed to an acid dye may stain the fabric but it will not be truly dyed and so will never be truly wash- or lightfast. Acid dyes are used on protein fibres like wool and silk.

So why do some fabrics bleed?

Fibre reactive dyes have a limited effective life span once they have been activated by an alkaline environment. The lifespan is dependent upon temperature but as a general matter, the dye molecules have all bonded either to fabric or to the water in 24 hours or so. After that time, the dye molecules are no longer capable of bonding with anything.

They can, however, stain fibres. Staining happens when a dye molecule gets caught between cotton fibres. This differs from dyeing, where the dye molecules actually bond with receptor sites on the cotton fibres and become part of the fibre itself.

Depending on the physical properties of the cotton and the fabric (whether the cotton was mercerised, tightness of weave, etc), staining can be permanent. An example of a stain that is quite permanent is indigo. Indigo doesn't form a molecular bond with the cotton fibres, it just lodges in the tiny spaces between fibres.

There is a product called Retayne, which acts to chemically fix certain types of fibre reactive dyes. The decision whether or not to use Retayne should be made keeping the ultimate purpose of the fabric in mind, since Retayne does contain formaldehyde and that formaldehyde is permanently added to the fabric.

Everyone should make up their own minds as to what their own safety standards are because there is nothing in life that comes without risk. Personally, I would not use Retayne on any fabric used for a quilt for a baby or small child because they do tend to put things in their mouths... but that's just my opinion.

Chemically, turquoise and fuchsia are the fastest striking dyes. This means that they bond the fastest, whether it is to the receptor sites on the cotton fibres or to the water molecules in the dye bath. They are also both quite temperature sensitive and won't bond properly at temperatres below 70 degrees F. If the manufacturer did not get the dye solution alkaline enough or warm enough, turquoise and fuchsia dyes will show the deficiency first.

bearisgray

MsE

Thank you so much for the info.

hobo2000

My main fabs are Jinny Beyer, cause I live close to her store and her fabs are so beautiful to work with, and Kaffe Fasset et al. I have never had a problem. I wash in cold water only and throw in a dye catcher and no problem. I never prewash as I like to enjoy the beauty of the fabric awhile before it has to be washed. Never looks the same after. LOL

raedar63

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