Black ink does most of the work in any Kenyan office. Invoices, delivery notes, KRA iTax returns, church bulletins and revision papers all come out in black. Built for small business owners, school bursars and cyber café operators, the HP GT51XL Black Ink Bottle keeps those jobs running at about KSh 0.43 per page, roughly one year of output for a busy school office. Cheap refill ink from unmarked bottles often clogs printheads within weeks. The HP GT51XL Black Ink Bottle removes that risk, because it is the exact formula HP designed the printhead to use, so nozzles stay clear and text stays dark.

Unlike other electronics retailers in Kenya that stock unlabelled refill bottles beside originals, Mascom International sells sealed HP stock with a checkable part number. One HP GT51XL Black Ink Bottle replaces roughly sixteen small black cartridges, each rated near 360 pages, and it fills the tank in under two minutes. Print shop owners along Moi Avenue report sharper text and fewer head-cleaning cycles after switching back to original ink. Walk in to match the HP GT51XL Black Ink Bottle against your printer model, or order by WhatsApp for same-day delivery across Nairobi and its environs.

It fits HP's ink tank printers that use GT51XL or GT53XL black ink. Common models include the DeskJet GT 5810 and GT 5820, the Ink Tank 115, 315, 319, 415 and 419, and the Smart Tank 500, 515 and 615. Check the label inside the ink tank lid or the ink section of your printer manual before ordering. If in doubt, send your printer model on WhatsApp and our team confirms the match within minutes, before you pay anything.

Both are 135ml bottles of HP pigment black ink rated at about 6,000 pages. HP labelled the older DeskJet GT and Ink Tank printers for GT51XL, then printed GT53XL in the manuals of later Smart Tank models. The ink sits in the same family and serves the same black tank. Many Nairobi offices run both printer types side by side. Before buying, confirm your model with our team, since HP updates its supply lists and we check each printer against HP's current records.

HP rates it at about 6,000 pages using the ISO standard test, which assumes about 5% page coverage, similar to a typical business letter. Dense documents such as spreadsheets with gridlines or scanned forms use more ink and print fewer pages. Light documents such as receipts print more. A school office printing 500 pages a month can expect roughly one year from a single bottle. That works out to about KSh 217 of ink per month.

Yes, if you already own an HP ink tank printer. At 6,000 pages, the bottle costs about KSh 0.43 per page. A small black cartridge in a cartridge-based HP printer typically prints about 360 pages, so the same volume would need around sixteen cartridges. For a SACCO branch printing member statements daily, that difference adds up to thousands of shillings saved every year. The original bottle also protects the printhead, which costs far more to replace than any ink.

Pigment ink sits on top of the paper instead of soaking into it. That gives sharper letter edges, darker text and better resistance to highlighter smudging and light water splashes. Colour inks in the same printers use dye, which suits photos and graphics. For contracts, court filings at Milimani and signed delivery notes that get handled repeatedly, pigment black keeps text readable for years. That is why HP reserves pigment ink for the black tank in these printers.

Refill ink sold in unmarked bottles varies in thickness and chemistry from batch to batch. Thick ink clogs printhead nozzles, and wrong chemistry can leave white lines across text within weeks. Replacing a printhead or the whole printer costs far more than the KSh 2,600 bottle. HP's printer warranty also excludes damage caused by non-HP ink. Original ink keeps the printer covered and keeps the rated 6,000-page yield honest, with fewer cleaning cycles wasting ink.

Open the ink tank lid on the side of the printer and remove the black tank cap. Twist open the bottle, peel the seal, then hold the nozzle upright over the black tank opening. Ink flows in on its own and slows as the tank reaches its fill line. If the tank fills before the bottle empties, recap the bottle and store the remainder upright. Close both caps firmly, then print a test page to confirm clean black output.

Keep bottles sealed, upright and out of direct sunlight on an indoor shelf. Heat thickens ink and moisture can affect the seal, so avoid windowsills in Mombasa, Kisumu and Lamu offices. In dusty areas along Thika Road, keep the carton closed until you refill. An opened bottle should be capped tightly and used within a few months. Check the date printed on the carton before storing spares, and use older stock first.

Three ways to order:

The bottle comes with the 6-month Mascom warranty stated above.

Schools, SACCOs and print shops nationwide buy their printer ink from Mascom International for sealed originals, clear part numbers and direct support from our Nairobi CBD store.