What is the most challenging specialty stitch you have ever stitched?
I would have to say coral knots. Not the ones that are done on the surface of a piece, it's a stitch done on one of the threads (warp? weft?) after you've cut some out. In English, that would be drawn thread. It looks like this. Now that I see that diagram, I can't figure for the life of me what I thought was so hard about it. I learned it in a class with Sue Stokes of the Nutmeg Needle. I haven't finished the project--a pair of Deco tulips surrounding a drawn thread sampler--mostly because I thought those knots were so hard. I may just have to pull it out. I'd have to say a lot of drawn thread stitches get me, though. I can't do a lovely dove's eye to save my life. If the pattern has four, I'll have one nice, two decent and one that's all wonky.
And lately, my Palestrina knots stink!