I find it useful to label my miniatures, to jog my memory in case I forget what they are, what they're used for, or where I got them from. But I don't like the markings to be visible, so I typically put the label on the underside.
And since many of my models have LITKO FlexSteel on the bottom – for storage in magnet-lined boxes – I've tried to write on that rubbery surface, but I find markers aren't fine-tipped enough and pens skip. So, as I've previously written, I find labels to be useful.
However, I recently spotted this product:
Crafter's Square Chalk Board Stickers (also known as Chalkboard Stickers) have recently become plentiful in the craft aisle at Dollar Tree in a wide variety of styles and shapes. These are intended not to be placed on a chalkboard, but to be written on with chalk or possibly white paint.
For $1.25 USD, you get 18 stickers in two sizes: roughly 1" and 2" circles. (Somewhat pricy for stickers.) They have a fine texture.
My first experiment was to try writing on one with a silver marker. To my surprise, the ink beaded up, though it did quickly dry in place.
Above, you can see the sticker placed on the bottom of my miniature base. The black color looks nice on the black FlexSteel. However, now that I've peeled off the sticker, I can tell why the ink beaded up – these stickers are plastic, not paper!
Now I am using a Gelly Roll pen. The ink still has a tendency to skip, but not as bad as if used directly on the FlexSteel.
However, by the time I've rubbed the sticker into place, much of the ink has abraded away. So I don't think this is going to work long term.
Bottom line: I won't be using these chalk board stickers on my bases.