Definitely blotter. On blotter it is quite durable. Dangers of light, heat, etc. are overstated and people keeping blotter in the freezer with vac sealing, desiccant, etc. is overkill if we're talking personal use amounts. For your own use any degradation that might happen is probably not even going to be subjectively noticeable. Even liquid in a sealed container which has been kept under relatively casual conditions apparently doesn't degrade as much as one might think: see reports about people dosing and tripping well from original Sandoz vials. Casually handled breath mint droppers not so much though. Crystal of course is pretty fragile and should be laid sooner rather than later to prevent any loss in potency.