Permanent marker fades, printed labels curl, and wooden sticks grow a tiny beard of mold. Pencil on cut-up yogurt lids is still the least annoying system I have tried.
The pencil line stays visible, the plastic bends without snapping, and the old lid is already waterproof enough for the job.
Current format
- Top line: variety.
- Middle line: sowing date.
- Bottom line: tray number.