I don't know the answer, but have you considered doing the embroidery seperatly and sewing it on the hat?

Yes, you can. Things to think about: Does the hat need to stretch where you are going to embroider? Will it be a bother to have stabilizer left after you embroider? If so, you might want to use a very sparse design. I have done some knit caps (we call them toboggans in the south, but I understand in the north that is a sled.) I used a sticky stabilizer that has paper stuck to the sticky side. you score it with a pin and remove enough paper to stick firmly the knitted hat then either pin or baste around it (making sure it is larger than your design). I would reccommend you stay around and watch the process to be sure the hat that you don't want stitched on doesn't commit haticide and jump under the needle. Otherwise it will be perfectly fine.;)

judy u have an answer from one of the best. jrob(jerillyn) can usually tell u what u know. She's an expert in all aspects of machine embroidery & has a heart made of gold. She definitelly knows what she says about hats commiting haticide I too, have personal knowledge about hats doing this. LOL *

Judy, I believe I would stitch it on some "Tuile Netting" and stitch it on after. Or as Jerrilyn suggest. *4U

If you have a felted hat it won't be too much of a problem...remember the embroidery will probably sink into the knitting...If it is a loose knit...then I would consider the tuile netting as Shirlene suggested!!

Judy I see jrob has given you a splendid answer, just a flower for you

I just did 6 knit hats with a varsity letter "E" last nite...but they were store bought...i used a med weight on back and WSS on the top! Had NO problems!

Judy I have embroidered on knitted goods and had no problem, Jrob has given you the advise , which is the way I do mine. *4u
Show us a picture of it once you are done.