"Best By" date on milk carton
Like milk, beer, and potato chips, large format ink cartridges also have a "best by" date.

Hopefully, in your sign making shop you are getting lots of orders, printing signs, banners and car wraps every day. But you may have noticed that your large format printer ink cartridges have a date of manufacture and/or an expiration date. Sometimes this is referred to as a "best by" date. What does this mean to you? How long is the ink 'Good'?

If your volume is high enough you are probably using your ink and media up before it gets the chance to age. But if you do have a stock pile of ink, here are a few things to keep in mind:

Ink doesn't 'go bad' the day of expiration. According to a Mutoh representative, the expiration date is "chosen based upon some degree of safety and performance". However, the ink doesn't really break down or 'go bad'. The pigments and the solvent carrier do tend to separate over time, though, so color can be inconsistent, and the settled pigments can collect and plug dampers. Plugged dampers lead to clogged ink lines which lead to clogged and destroyed heads. So, it is important to be cautious if using ink over 2 years old. To be safe, you may want to discard that old ink and go with a fresh cartridge.

Store and maintain the ink properly. Mutoh and SIGNWarehouse recommend 'turning' the extra ink cartridges that you are storing. Shake them and flip them over every month, 180 degrees in both directions - sideways and end over end. That way the pigments get a chance to mix and move.

  1. Store them in a cool, dry location, as well. A climate controlled closet or shelf is best. Avoid extreme temperatures and frequently changing temperature. Extreme heat is worse than cold. Heat will cause faster separation.
  2. There is no danger that the ink will freeze, as the solvent in the ink is a glycol ether, in the same chemical family as antifreeze. But, you don't want to run the ink cold. Cold won't hurt the ink, but will change the density and other characteristics that affect drop formation.
  3. Don't use hot ink, either. Allow the ink cartridge to reach room temperature before using it in your printer.
  4. That same practice should be observed for your media. Don't get it straight off the UPS truck, load it and print. The media, whether hot or cold, will not accept the ink properly at extreme temps and you won't get the beautiful prints you desire. Let it reach room temp, as well.

We recommend that you always keep at least one spare ink cartridge of every color so that you don't get caught short. Two is an even better idea. Each cartridge has a computer chip card on the side. From time to time, a cartridge could be damaged or a chip can be dirty/damaged/incorrectly positioned, causing the printer to reject the ink cartridge, rendering it useless until the chip card is repositioned or replaced. If you have TWO spares... you're certain to have one at the ready when you need it.

SIGNWarehouse can replace a damaged card. You can reposition a misaligned card by peeling it off and replacing it correctly. Use a good ink cartridge as a guide. Following these suggestions will give you the best print quality and happy, satisfied sign customers.