The ink drys fast and erases cleanly, leaving no excess color behind

For the faint colors I tried storing them in a cup for a couple days cap side down to see if maybe the ink was in the other end of the marker - no luck - they're still too faint to be useful.

The ink is really faint; therefore I decided to not use those two markers.

The ink will stay darker that way.

College is expensive and I hardly had money to purchase these just so I can write with invisible ink on my damn whiteboard.

Although the colors are great the ink seems faint for dry erase markers.