M3D or Micro3D has a very wide variety of filament types to meet any need. M3D sells spools by the length, however don’t let that confuse you when buying. 250ft is about the same at 250g when comparison shopping. The other sizes are 500 and 1000ft. For a filament which you may not need to use a lot, these smaller rolls can save you money. M3D often has filaments listed out of stock and some filaments are not available in the larger, more economical, sizes. M3D does release MSDS sheets and detailed print settings for all their filaments. M3D also puts a 3 letter code on the filament rolls which allows rapid slicer settings if you own an M3D printer. M3D provided many samples to help this site grow.