Yes, inkjet ink does expire.
And using expired inks can damage your printer.
In this article, we’ll explore the basics of ink cartridge construction, the factors that affect inks, what happens to old ink,, and why using expired cartridges is a bad idea.
But before we dive into the arcane territory of ink formulation, it’s important to understand the ins and outs of an inkjet cartridge.
Anatomy of an ink cartridge
Here’s a simplified way of thinking of ink cartridges:
Cartridges are made up of ink in a pouch, integrated circuit chips, and a plastic housing.
Let’s start with ink which has two main components:
- The pigments are small, micron-sized particulates that provide the color that is sprayed onto paper to make a print. Pigmented inks provide increased longevity compared to dye based inksets, but the particulate formulation can settle out of solution as the ink ages.
- The Solution suspends the pigment allowing it to be transported from the cartridge, through the printhead, and onto your paper. This solution can be water-based (aqueous) or alcohol-based.
Dyes are an alternative to pigments. Though similar to pigments, dyes dissolve in solvents, similar to the way sugar dissolves in water, instead of being suspended in a solution. Dye based inksets may have a longer shelf-life, but prints made with dye inks tend to have a permanence rating measured in months rather than decades.
Inks are typically sealed inside mylar bags housed in the larger rigid cartridges.
The business end of an ink cartridge has an integrated circuit stuck to the top. These chips repor tink levels, ink color, and certify that inks are genuine.
Lastly, the plastic container houses the ink. It sits in the printer and interfaces with the pressurized ink delivery system to keep air bubbles out of your print head
That about does it for ink cartridge components and construction.
Let’s take a look at the lifespan of stored ink and how expiration can lead to problems with print quality.
The lifespan of stored ink
It’s important that inks are stored properly to keep output consistent and to keep printers working as reliably as possible.
The factors that affect ink and can lead to spoilage are:
- Length storage time on the shelf
- temperature consistency and extremes
- exposure to sunlight
- Sealed or open
To achieve the longest shelf life, ink must be stored at a stable room temperature, kept away from direct sunlight, not opened until the ink will be used, and consumed within one year once placed in the printer.
What happens when inks expire?
In a pigmented ink set, the particulates suspended in the solution will settle out of the fluid and collect at the bottom of the cartridge. Using settle ink in a printer will result in more frequent nozzle clogs and a shift in color as the pigment load differs from the expected formulation.
Air can get inside an old ink cartridge, causing the ink carrier solution to evaporate. The result is that old ink can become sludge rather than the normally thin liquid. Ink sludge can clog your printer’s ink-delivery system and destroy a print head.
It’s also worth noting that water-based (aqueous) inks can become moldy, which can lead to nozzle clogs and other ink feed problems.
The expiration date on your ink cartridges is designed to keep all of this from occurring.
Using expired ink can cause problems
There are two main reasons to not use expired ink in your professional inkjet printers.
1. Expired ink can affect color accuracy.
The ink may be streaky or appear less vibrant than fresh, non-expired ink. Print quality is reduced and color accuracy is hard to achieve.
Contract proofs, display images, fine art prints, and most any type of high-quality inkjet print can be compromised by using expired ink. Expensive and highly visible projects aren’t something to take a chance on with old ink.
2. Expired inks can cause print head clogs.
Expired ink may lead to irreversible printhead clogs that could destroy the printer. As we covered earlier, pigmented ink will settle and the solution will turn to a sludge; aqueous inks can contain mold. Is an expired ink worth the risk of not only damaging your printhead, but causing unnecessary downtime with a financial impact (up to $2,000)?
Spectraflow strongly recommends maintaining non-expired inks in your professional printer at all times.
That being said, if the printer is not mission critical and precision color accuracy is not important, then expired ink can continue to print until the printhead is destroyed. Extended agitation (shaking each ink for ~10 minutes) is a good idea, but no amount of shaking can ensure that expired ink won’t cause permanent damage to the printer.
Ink may be costly, but a new print head is costlier. To keep your expensive printer running smoothly, make sure to store your ink cartridges properly and use inks in a timely manner. If your inks have expired, invest in new cartridges to avoid the downtime, lost revenue, repair cost, and needless frustration that is easily avoided by keeping ink fresh.