Whatever that means
TFP had the bright idea of adapting as saddle attachments the little Scotrail toilet bags we both carry our toolkits around in. Turned out sewing the strap on means a fair bit of unpicking to get access to the side panel. Still, that revealed both how well made they are (especially when they’re a little throwaway thing that most people leave behind (and I assume the staff scoop them straight into the bin, so I had no compunction picking up all the ones I saw left behind on my last trip.)) but also how easy they are, especially if you do away with the need for zips.
So, with the afternoon off work, I set about making one out of waxed cotton and the plastic cut from an old storage bag. Worked out OK. At my level of proficiency, contrasting thread was probably not the best idea.