Dr. Brat wrote:

The reference to silk was to one of Tanja Berlin's Jacobean kits. Is
Jacobean a form of crewel, or is it its own genre?

Jacobean Crewel is a "genre". 2-ply crewel wool on linen twill (less
often plain weave linen). A time period of "design style" as well.

But I think it's great to expand it to silk. :-) Hooray for Tanja.

The use of crewel wool for shading (just like silk on silk
needlepainting) is also gaining ground, as is more abstract use of crewel.

Dianne