Flying with Ink??

[cbrfan]

Stupid question, I know. But I want to order my water from Staples to be delivered for our trip to POR. I need a $50 purchase to get free shipping from Staples and I thought since I always seem to need ink for my printer that it would be small enough to take on the plane home and meet my $50 minimum purchase. The question is....are ink cartridges considered a liquid? I'm afraid they'll burst if I pack them in my checked luggage so thought I'd put them in my carryon if I can. Anybody know??