[New Perspective]

When you fax them back, just fax as many pages as possibe with the darkest and most print that you can fit on a piece of paper. For me, a very very large black square works well.

[John Jorsett]

When you fax them back, just fax as many pages as possibe with the darkest and most print that you can fit on a piece of paper.

No need for multiple pages. For easy fax vandalism, just get a long piece of paper, such as the fanfold printer type, feed it into the machine and tape the ends together. Fax until the receiving machine runs out of paper/toner or just craps out altogether.