Sometimes they pool and you can ruin your project

Has ruined several projects.

The project was ruined

The color would suddenly spurt out and instead of a nice small dot or line you would get a big blob of color, ruining the project

It ruined the project I was working on

I bought these extra fine point paint pens to clean up an art project I was working on

If you 'push' the line away from you (as you would if you're writing cursive and you are writing the letter "O"), you will get some feathering unless you ease up on the pressure.