Sponge vs. Spongeless Refill Kits for HP 68 Cartridges: Which Offers Better Ink Yield?

 Question:

Thank you for the helpful videos and great products! I’m wondering—when it comes to refilling HP printer cartridges like the HP 68, is there an advantage to using the sponge-style refill kit compared to the spongeless modification kits?

Answer:

Comparing Refill Methods: Sponge vs. Spongeless for HP 68 Cartridges

To evaluate the benefits of sponge vs. spongeless refill methods, we conducted a side-by-side test using a controlled environment and consistent test materials. We used the BCH-designed test page, which is similar in ink usage to HP's standard ISO/IEC 24712:2007 test page—a benchmark used to determine page yields for ink cartridges.

Here’s what we found across three refill approaches:

1. Standard Sponge Refill (Original Cartridge, No Modifications)

In our first test, we used a standard HP 63 XL cartridge (which behaves similarly to the HP 68 XL). After refilling the built-in sponge with ink and performing minor unclogging, the cartridge was able to print approximately 97 BCH test pages, which translates to about 185 ISO-equivalent pages.

Performance: Comparable to HP’s official specs of 165–190 pages for this type of cartridge.

2. Modified Sponge Cartridge (Sponge Replacement)

Next, we surgically opened the cartridge and replaced the small OEM sponge with a larger sponge, allowing for increased ink storage.

The result? The upgraded sponge cartridge printed 269 BCH test pages, which equals around 511 ISO-equivalent pages.

Performance: Similar to what HP 63/68 XL cartridges are rated for—roughly 300 to 500 pages.

3. Spongeless Cartridge with Air Pressure Regulator

For the final test, we removed the sponge entirely and installed a special refill cover with a built-in air pressure regulator, turning the cartridge into a true spongeless refillable model.

This configuration gave us the best performance: 407 BCH test pages, or approximately 773 ISO-equivalent pages.

Performance: That’s 68% more than the HP XL version, and over 4 times more than a regular starter cartridge!

Which Is Better?

If your goal is maximum page yield and ink efficiency, the spongeless kit is the clear winner. By utilizing the full interior space of the cartridge for ink, you eliminate the volume occupied by the sponge while also managing internal pressure correctly via the regulator.

However, the spongeless mod is a Level-5 advanced project. It involves cutting, gluing, and a bit of precision work. We recommend it for experienced refillers who are confident in their handling of cartridge internals.

If you prefer a simpler, safer upgrade, replacing the sponge with a larger one offers solid gains and keeps the refill process more familiar.

You can view our full test process and video breakdown here:
Watch the Cartridge Refill Test (https://www.youtube.com/embed/yBKUsDgyTbQ)

A Quick Note on Our Services

Printer upgrades and modifications often require hands-on work and careful handling, which is why we don't offer remote diagnostics or repair guidance. However, we do provide in-person printer evaluations and repairs through our diagnostic center (https://bchtechnologies.com/printer-repair-service) on a first-come, first-served basis. Please note there may be a wait time of several weeks due to high demand.

If you prefer to DIY, we strongly recommend browsing our YouTube channel (https://youtube.com/@bchtechnologies) and using the search bar next to the "About" tab to find specific topics. We’ve produced hundreds of videos over the past nine years, and searching is the best way to locate exactly what you need—including potentially helpful videos from other creators.

Thanks again for your thoughtful question and for being part of our BCH community. We're excited to see what you accomplish with your refill projects!