Excellent concept with some minor weaknesses

The bottom line first: The pins are incredibly handy and absolutely worth the money. You have helped me in teaching the use of OHP, and every now and then makes minor corrections without the risk to blur what is represented.

The color choice is very well done and also the yellow is justified, as it can be seen to good OHP or can be used for marking as CDs, in addition you can thus mix colors, what eg particularly works well with the green.

The weaknesses of the pins I see more other place. On the one hand they are not really waterproof: I tried my writing names on a toothbrush and this mark was barely recognizable after the first brushing and also in an experiment in class unfortunately I found shocked that it was not with the water resistance so far away is a mark on a glass, outside !! !! mind you, has been completely replaced by condensation.

And secondly the erasers are very small and close very quickly if you want to perform more corrections. Therefore I strongly recommend to work with larger corrections with rinsing water or alcohol.

But so far no me better transparency pens are staying and so I will continue to work briskly in the classroom!

Best Regards
Aven