I too use a label machine for all the different kinds of stakes I use. I even tried it on one of those smooth stones today and so far it looks like it will stick. Tomorrow a few are going outdoors for the acid test (rain tomorrow night predicted). Speaking of grease pencils, I have looked for months for white ones and finally found some on a dusty, unused shelf at the building supply yard, of all places. We like to mark the outside of the black plastic gallon pots in case our stake(s) disappears from the inside. Cathy Craig President PBS Maritime zone 9b