Next week is Bumbershoot, a big outdoor festival in Seattle. I'm planning to be there for most of the 3-day weekend, and given that the ground in Seattle is pretty much always damp, I wanted to have something to sit on that I could cram in my bag. S__ M__ and E___ G_____ can confirm the potential dampness of Bumbershoot, S___ in particular. Similar to the Mackintosh square, it's meant to be mostly waterproof, and to protect the user from "damp grass and cold marble". The top is a a heavy-ish canvas and the back is the tent bottom fabric. There's a thin batting in between, and the corners have fabric strips that I can use to hook it onto the outside of a bag. The canvas fabric is from Repro Depot, and I got the nylon on the back at the Seattle Fabrics booth at a sewing expo. Both have been in the sewing room for months and months, along with a big grommet setter that I couldn't quite get to work today. Hence, no corner grommets. The square is about 25" or 26", big enough to sit cross-legged and (hopefully) keep people out of my personal space. I've never quite gotten over the Personal Space Crisis of 1988 or 89, when a hippie at a Grateful Dead campground woke me up to ask for a hug. That is not an exaggeration, either--if anything, I'm understating the horror.
An added bonus is that my square matches perfectly the 25 year old vinyl flooring in our kitchen.
Product testing results (as well as photos & talk about Bumbershoot) will be posted during and/or after next weekend.