Seed-starting cell kits
For years I have used the commercial cell kits for seed starting. I usually cut the cells into groups of threes or fours so I can remove the earlier germinators and move them around. I find them useful and convenient.
This is my gripe: Why don't the manufacturers of these devices make them out of a clearer or translucent plastic like a milk jug? I'm sure I am not alone in having kept starts in original cells too long, only to find that the starts are hideously root-bound. Translucency would help give early warning that "it's time to pot up!"
BTW, on the few occasions when I have bought small starts at a totally reputable farm-and-garden place, I've also experienced root-bound babies, so I don't think I'm at sea on this issue.
Just a thought and an idea...FWIW.