Eliza Wright Hints and Tips Silk Shading Silk Shading Materials
A top surface fabric and a backing fabric will be needed. For landscapes that are stitched all over, both the top fabric and the backing fabric should be white.
For the top fabric I usually use a fairly robust silk such as Habotai 8, the sort that is usually used for silk painting. Many people use silk Dupion, but this is made from slub silk, and the resulting irregularities in the weave make it unsuitable for all-over stitching. It's not essential to use silk, but I find that the fineness of the weave goes well with stitching using one strand of stranded cotton. Also it is translucent, making it easier to transfer the design.
For the backing, I use a cotton fabric. To discover which backing fabric would be best for your project, there's no substitute for trying it out. Remember you're going to be pushing the needle through it hundreds of times! Mount some up in your hoop (without the silk) and pierce it with a new embroidery needle, threaded with the thread you'll be using for the embroidery. Push it all the way through. There should be very little resistance. If you have to struggle to push the needle through, then the cotton backing is too heavy. I usually find that most muslins are too flimsy, and light weight calico is bordering on too heavy. Light weight curtain linings often work very well.
It isn't necessary to use silk thread. In fact for your first attempt I would suggest you use stranded cotton, as it's much easier to handle. For all my landscapes up to now I have used just one strand at a time. This gives a fine finish with a moderate lustre.
If you want to use silk, be aware that there are different kinds of embroidery silk available, some types are soft with a matt sheen and others have a beautiful lustre. The latter is brilliant for water but not so good for hills and bushes which do not generally gleam.