HP DeskJet 3720 Ink Cartridges
Your HP DeskJet 3720 uses the 65 series ink cartridges, consisting of one black and one tri-colour cartridge. We have been supplying consumables for this printer since 29 Jun 2021, providing both genuine HP and cost-effective compatible alternatives. This two-cartridge system is common for home use, where the printhead is built into the cartridge itself. This design ensures that every time you replace an empty unit, you are also installing a fresh firing mechanism, which helps maintain print reliability even if the printer sits idle for several weeks between uses.
Choosing the right cartridge setup
Managing your replacements depends largely on how often you print. If you only print occasional school assignments or return labels, the standard 65 cartridges are a low-entry-cost option. However, most users find the 65XL high-yield cartridges more economical, as they contain significantly more ink for a lower price per millilitre. If you prefer to save further, our compatible 65XL cartridges offer a high-capacity alternative with a money-back guarantee if they do not work to your satisfaction. You can view our returns policy for full details.
Free delivery applies on all orders over $99 (conditions apply). We ship directly from warehouses in Perth, Brisbane, Sydney, Melbourne and Adelaide to ensure your HP ink cartridges arrive as quickly as possible.
Expected page output and replacement cycles
Page yields for the 65 series are determined by the ISO/IEC 24711 standard for inkjet printing. Under this standard, the black 65XL is rated for approximately 300 pages, while the standard black 65 is rated for around 120 pages. In a home environment, your actual yield will vary based on the density of text and whether you perform frequent head cleanings, which consume a small amount of ink from both cartridges.
| Cartridge Number | Type | Colour | Page Yield | Cost Per Page |
|---|---|---|---|---|
| 65 | Standard | Black | 120 | $0.28 |
| 65 | Standard | Colour | 100 | $0.37 |
| 65XL | High Yield | Black | 300 | $0.24 |
| 65XL | High Yield | Colour | 300 | $0.29 |
Cost Per Page = Total Cartridge Price ÷ Page Yield (at 5% coverage). Prices based on Genuine cartridges.
Genuine vs compatible cartridges
We stock both genuine HP 65 cartridges and premium compatible versions. Under Australian Consumer Law, using compatible cartridges does not void your printer warranty. This allows you to choose the best value for your budget without risking your printer's protection. For a deeper dive into the differences, you can read our guide on genuine vs compatible cartridges.
Pro Tip
Because the HP DeskJet 3720 uses a tri-colour cartridge (Cyan, Magenta, and Yellow all in one), the entire cartridge must be replaced once any single colour runs out. To get the most life out of your colour ink, avoid printing images with large blocks of a single solid colour, as this will deplete one ink chamber faster than the others and force an early replacement.
Frequently Asked Questions
Can I install a 65XL cartridge if my printer came with a standard 65?
Yes, the 65XL and standard 65 cartridges have the exact same external dimensions. The "XL" designation refers to the volume of ink inside the cartridge, not the physical size of the plastic shell, so it will fit perfectly into the same slot.
Why does my printer show an "Ink Low" message shortly after installing a compatible cartridge?
Sometimes the printer software remembers the chip data from the previous cartridge. If the printer prints normally, you can usually bypass these prompts. Our compatibles are filled to the maximum capacity, but the digital ink level on the screen is an estimate based on page counts rather than a physical float sensor.
What happens if I only replace the black cartridge and leave the empty colour one inside?
The HP DeskJet 3720 requires both a black and a tri-colour cartridge to be present in the carriage to complete the circuit. While you can often set the printer software to "Black Ink Only" mode to conserve colour ink, an empty or missing colour cartridge may eventually trigger an error that prevents the printer from starting a job.
