For ink pens that won't write; place the pens upside down in a cup of hot water until the water cools off. Wipe dry and use.
Source: My husband does this and it works very well.
By Monica from Cortez, CO
This is a page about reviving ball point pens. One way to get the ink flowing in a clogged ball point pen is to apply heat to the tip. Here is some information to try before you throw that pen away.
General consensus seems to be that the best way to jumpstart a gel glitter pen is to bounce the tip on a hard surface. Shaking it can also get the pen working. This is a page about a new gel glitter pen not working.
Sometimes there is plenty of ink left, but the marker tip has dried out. This is a page about reviving dried up markers.