Interesting. Here's the link:

Here is a link that might be useful: plant markers

That's cute. That's really cute.

My friend was telling me about using aluminum cans for this purpose. The cans are made so thin nowadays so they're easy to cut. I couldn't picture it, now I can.

When I did this years ago I found that eventually the oj lids started to darken and/or rust making it difficult to read.

I haven't tried cutting al cans, worried about getting cuts on my hands from sharp edges when I am working in the garden. Perhaps the edges could be rolled someway.

For now I use mini-blind markers or plastic knives which invariably get stepped on and broken. Sometimes I push the marker just below the soil or around the crown where it isn't seen but I can find it if needed. Usually after a short period of time I know which plants are where so marker can be removed. I also make a rough drawing of my gardens noting new plantings and late returning plants.