I've seen some light-ish spots on Kona black when ironing. I think it's only when there's some dampness - after they dry out you can't see anything anymore.

I've washed a couple lap quilts made with Kona black countless times (we have very snuggly dogs!) and there is no spotting/fading going on.

I think it's probably fine. :)

I don't think it is my water as I took some material to work and used the water there also. Same thing happened. I was going to call fabric.com, but they were closed due to weather. I will try to call them tomorrow. I think I will go ahead and wash the fabric and see what happens.... Thanks for all the responses!

It happens to me, too. More so on some colors than others, but it happens. Everything looks fine when the quilt is washed and dried, so I quit worrying about it. The first time it happened I nearly had heart failure on the spot, though.

I've had fabrics whose tone seems to darken when ironed. They have all recovered those when they cooled/dried.
MaryKatherine

It happens on a lot of Kona colors, and on Moda and other solids as well. It probably also happens on prints, but you just don't notice it because of the pattern. It's a fact of life, but has never resulted in a permanent change of color in my many years of using Kona Solids extensively.

If you want a reliable, definitive answer, call Kaufman directly, not fabric.com.

Kaufman does not make seconds per an earlier thread here on the Quilt Board. Someone had contacted them and they asked to become a member so they could comment directly.

I had some Kona beige batik that did that but the spots disappears when it dries.

I have found that bright KONA colors will darken with heat from the iron (I dont use water) but I have never noticed discoloration, temporary or otherwise. I have bought from JAF and LQS and internet shops.

This is funny as I bought some Kona from HL & had the same thing happen I was baffled as was grand daughter. I thought maybe HL put the fabric on an empty Kona bolt, but in the end the spot did disappear. My spot was the mirrored image of my iron. I thought I scorched it some how with only a few seconds on the material?? Glad to see this on the board.

That's how I realized that I have to clean my iron again. One of my Kona Reds has ugly spots on them. Hope they come out after the wash.