This is how I do it. Works great, just be very careful not to nick the fabric.

Great idea! I am really trying to avoid separating the layers as I glue basted this quilt. Have been dabbing it with warm water to open it up, but seems like that process is taking forever, too.

I've been saying lots of prayers, and asking forgiveness for my thoughts and words, thru this process. And yes, even with the magnifying glass and lots of light, these old eyes are straining almost out of their sockets.

I love my seam ripper with the very thin, small, curved blade. It's actually designed to rip out serged seams, but works fantastically on small stitches. I've found it especially useful on the small stitches such as used when paper piecing.

As to the black on black, I'd recommend doing it right under an Ott light or some such and get every 3-4 stitches. Once you get a tiny area opened up, you'll be able to spread the seam apart somewhat and get to just the thread a bit easier.

Hope this helps.

Have you tried an electric seam ripper? It does a nice job of cutting the thread without hurting the fabric. Use the ripper with a light touch...don't force it.

Can you get into the seam? I didn't know (or had forgotten), that little bead of plastic on the short end of the seam ripper has a use. Turn the ripper so that little bead is on the underside of what you want to open up, take a deep breath and start pushing it into the stitches. That little bead seems to guide the ripper. Clipped threads will collect in the ripper so take it out and remove those every few stitches. Good luck! (You might want to make a sample line of stitching to try this before working on your "good" piece so you understand and feel a little more confident in what you are doing? Otherwise that method of clipping every few stitches and pulling the thread on the other side works really well, too.)

Using the small curved blade seam ripper will get it done fast. Separate the layers and cut the threads as they open up when you pull on both layers. So it's one hand on the top layer, one hand on the bottom layer and one hand on the seam ripper. That's three hands, right? You have three hands! I put the bottom layer under the presser foot and put the needle down just so that the fabric is caught. Gently tug on the top layer as you cut downward with that curved blade. The blade will cut the third or fourth thread down as the fabric separates.

I gave a demo at our quilt group on how to do this, but didn't have my sewing machine handy. I had a C-clamp, so clamped the bottom layer to the table edge for my third hand. I could undo a WOF seam in just a few minutes. (Yes, I sewed way too many of my strips together when they should have been added in a "quilt-as-you-go" method.) Didn't take me long to undo them all.

I agree with Tartan, that is the way I carefully rip out small stitches.

I have tried some of these methods, not the rotary cutter though.
I am finding white on white is hard to see also.
Good luck and just take your time.

That's the sort of thing that I do a small amount and put it aside in frustration.....sorry for you.