One thing that really makes long arm cross stitch look nice is the shine off silk provides a directionality and flow for the stitching. My spun silk is soft and nice, but not as great on shine. I rummaged until I found a box of cheap sari silks that I bought a few years back on an impulse buy. They aren't the nicest silk, but they have a great shine! I debated ground fabric for a while. I pulled out several great options - evenweave linen, some monaco cotton, and some aida. Ultimately, I surprised myself went with the aida. I have lots of it floating around. The aida is designed for cross stitch and it makes stitching easier in challenging circumstances. A lap project should be friendly and I figured there would be less squinting and fidgeting with those perfect little squares. The aida makes for a heavier ground than the linen does, but the stiffness also means I don't need a hoop - which is another plus for portability.
Now that I've made some progress, I can confidently say that this is a great lap project! The aida makes life easier and the silk has amazing shine. I really, really love the texture of the stitching; it makes an interesting geometric pattern really beautiful. The silks are as fussy as I remembered and they have these little slub chunks that are truly infuriating, but they were cheap enough to use on random projects. The first square was very easy to stitch, with almost no counting. I just followed the stitch lines and the geometry remained true. When it came time to start the second square I realized I needed a method, but the counting turned out to be very easy for this design. I haven't really figured out the final parameters of the project, so the connecting knot work on the edges is left open until I make some decision. I think if it's a pouch then it should be at least two squares in width. The ground is an 18 count aida to give some scale.