What Ink Does the Epson WorkForce ET-4550 Use?
Last Updated:Quick answer: The Epson WorkForce ET-4550 EcoTank uses Epson 774 pigment black (T774120-S) and Epson 664 Cyan (T664220-S), Magenta (T664320-S) and Yellow (T664420-S) ink bottles. Castle Ink sells a compatible 774 + 664 4-pack for $29.99, plus 774 Black (140 ml, $9.99) and 664 Cyan, Magenta and Yellow singles at $8.99.
The ET-4550 was one of Epson's first U.S. EcoTanks, launched in 2015 for home offices. It shares this ink setup with the Expression ET-3600 and the wide-format WorkForce ET-16500. The cheaper ET-2500, ET-2550, ET-2650 and ET-4500 use the same 664 colors but a 664 black instead of 774.
CastleScore · November 2026
87/100 — Highly Recommended
Epson WorkForce ET-4550
| Pillar (weight) | Score | What it is based on |
|---|---|---|
| Owner ratings (28%) | 86 | 4.4★ across 739 ratings at Best Buy (89% would recommend) |
| Expert reviews (18%) | — | No published numeric expert score we could verify. |
| Cost per page (24%) | 99 | About 0.12¢ per page blended with our 774/664 4-pack ($29.99: 6,000 black + 6,500 per color pages at Epson's ratings). |
| Reliability (13%) | 74 | Most-reported problems: document feeder misfeeds; lines across prints after a year or more of use; slow print speeds; a 20-minute initial ink charge |
| Features (12%) | 82 | Print, copy, scan, fax; 30-sheet document feeder; auto two-sided printing; Wi-Fi, Wi-Fi Direct, Ethernet; small LCD. No borderless printing, no touchscreen. |
| Value (5%) | 84 | Running cost and owner satisfaction against a launch price of $499 |
Limited data: We could not find a published numeric expert score for this printer, so that weight is spread across the other pillars.
Discontinued. Epson launched the ET-4550 in 2015 at $499 and no longer sells it new. Epson 774 and 664 bottles are still sold.
CastleScore is Castle Ink’s own editorial rating, built from retailer star ratings, expert reviews, real cost per page and owner complaint patterns, checked November 8, 2026. It is not a customer review. See every ranked printer or how the score works.
The ink, pictured
Epson 774 + 664 4-packBlack 140 ml + C/M/Y 70 ml
Epson 774 BlackT774120-S · 140 ml
Epson 664 CyanT664220-S · 70 ml
Epson 774 + 664 4-pack
Epson 774 Black
Epson 664 CyanOur own compatible 774 and 664 bottles, made in the USA.
What Ink Bottles Does the Epson ET-4550 Take?
| Bottle | Epson part no. | Size | Approx. yield (Epson) | Castle Ink option |
|---|---|---|---|---|
| 774 Black (pigment) | T774120-S | 140 ml | ~6,000 pages | Compatible, 140 ml, $9.99 |
| 664 Cyan | T664220-S | 70 ml | ~6,500 pages | Compatible, 70 ml, $8.99 |
| 664 Magenta | T664320-S | 70 ml | ~6,500 pages | Compatible, 70 ml, $8.99 |
| 664 Yellow | T664420-S | 70 ml | ~6,500 pages | Compatible, 70 ml, $8.99 |
| 774 Black + 664 C/M/Y | — | — | — | 4-pack, $29.99 |
Yields are Epson's ratings. The 774 black is pigment ink for sharp text; the 664 colors are dye. Some retailers also list Epson's 664 dye black for this printer, but 774 is the black Epson ships in the box, so stick with it and never mix the two in the same tank.
What Does ET-4550 Ink Cost per Page?
Our 774 black is $9.99 for about 6,000 pages (about 0.17¢ a page) and each 664 color $8.99 for about 6,500 (about 0.14¢). With the $29.99 4-pack it's roughly 0.12¢ a page blended. Computerworld noted that Epson's own replacement set cost about $58 when the printer launched.
How Do I Refill the Epson ET-4550?
- Check the ink levels in the tank unit on the right side of the printer.
- Flip open the tank unit cover and remove the cap from the tank you're filling.
- Open the bottle and pour slowly into the tank until it reaches the upper line; this older design doesn't stop the flow for you, so watch the level.
- Recap the tank and close the cover.
- Reset the ink levels from the printer's menu so the low-ink warnings stay accurate.
Work over paper towels; reviewers found the original bottles easy to spill.
Which Other Printers Use Epson 774 and 664?
774 black plus 664 colors: the Expression ET-3600 and WorkForce ET-16500. 664 colors with 664 black: the Expression ET-2500, ET-2550, ET-2600 and ET-2650 and the WorkForce ET-4500. See all Epson 664 and 774 ink bottles.
What ET-4550 owners ask
These come from Best Buy and Adorama reviews and reviews from Computerworld, TechRadar and Expert Reviews, answered in our words.
Why does setup take so long?
The first time you fill the tanks, the ET-4550 runs a 20-minute initial charge to pump ink through the tubes and clear air. It only happens once.
The document feeder keeps misfeeding. Can I fix it?
It's the most common ET-4550 complaint. Fan and square the stack, load fewer sheets, and clean the feeder's pickup roller with a lint-free cloth lightly dampened with water.
Why are there lines across my prints?
Usually clogged nozzles. Run a nozzle check and a head cleaning from the maintenance menu, then let the printer rest before cleaning again. If lines persist after several cycles, the print head may need service.
Can it print borderless photos?
No. It's an office-focused model without borderless printing.
ET-4550 quirks worth knowing
- It prints, copies, scans and faxes, with a 30-sheet document feeder and automatic two-sided printing.
- Epson rates it at about 13 pages a minute in black and 7.3 in color; reviewers found it slow.
- It has Wi-Fi, Wi-Fi Direct and Ethernet.
- The ink tank unit sticks out from the right side, so allow extra desk width.
Frequently Asked Questions
What ink does the Epson ET-4550 use?
Epson 774 pigment black (T774120-S) and Epson 664 cyan, magenta and yellow (T664220-S, T664320-S, T664420-S).
Does the ET-4550 use the same ink as the ET-4500?
The colors are the same (664), but the ET-4500 uses 664 black while the ET-4550 uses 774 pigment black.
Can I use Epson 502 ink in the ET-4550?
No. Epson 502 is for newer EcoTanks like the ET-2850 and ET-4850. The ET-4550 takes 774 and 664.
Other printers that use Epson 774 / 664
More Epson ink guides: Epson EcoTank ET-4850 · Epson EcoTank Pro ET-5170 · Epson EcoTank ET-2980 · find any printer
Replacing it? Our highest-rated alternatives
- Epson EcoTank ET-2980 (cheapest to run) — CastleScore 90
- Canon PIXMA MegaTank G3290 — CastleScore 88
- Canon imageCLASS MF275dw (laser) — CastleScore 81
Sources
Ratings and prices were checked on November 8, 2026 and will change over time.
Need replacement Epson ink cartridges? Shop Epson ink cartridges at Castle Ink. Remanufactured, up to 70% less than OEM, and shipped the same day when you order by 4 PM ET.