If I can’t find a convenient way to do away entirely with mechanical keys (primitive, clanking, medieval relics in my pocket) then at least I can spare myself the problem of ‘which key should I use for this door?’
Rather than stick on coloured tabs etc, today’s invention is to make a set of plastic holsters to accommodate one’s keys. The purpose of each would be indicated by the shape of the holster into which it has been slid (as shown).
