A few years back, I moved up to 1mm Tortex blues. For everything, electric and acoustic. After a discussion with some folks about acoustics, some folks use different (thinner) picks for that. I bought a sampler pack and found that I like the .73mm (or maybe .88mm) Flex Tortex. They seem to give a little more "snap" when playing acoustic. When I go back to the 1mm, it felt a little "dead" or "dull". At one point, I really liked the 1mm blues. Maybe my ear has changed but got me thinking do picks ever wear out? Not lose the edge, but just tire out? (I don't lose things, so anything I use tends to have been around a while).