Roto, Labella and Pyramid I know for sure (because I own or have owned sets). Höfner makes shortscale strings too. That said, unless your short scale has whimpy pegs (Höfner) or very small holes in the pegs (banjo tuners), long scale strings fit on short scales, especially on one with man size tuners such as the SG RI. If Gibson doesn't bother with short scale roundwounds when stringing them at the factory, why should you with flats? But help is on the way: Send me your postal address and I'll send you a fresh set of Pyramid "Gold" (they're not, just branded that way) nickel flatwounds in shortscale. They're probably hard to get where the 'roos live and I bought more than a couple of them a few years ago. At the rate I change flatwounds, my grandchildren will one day have to throw them away unused wondering why "grandpa hoarded all this stuff". The E on those, btw, is a 100.