Expression ET-3700
The Expression ET-3700 shipped with two full sets of 502 ink — two 127 mL black bottles and two 70 mL bottles of each color — a hint of the volume this EcoTank was built for. Refills stay in the 502 family: black up to 7,500 pages per bottle, colors up to 6,000. Compatible Clever Supplies 502 bottles are below.
| Bottle | Type | Color | Approx. Yield |
|---|---|---|---|
| Epson T502120 (compatible) | Pigment ink bottle, 127 mL | Black | 7,500 pages |
| Epson T502220 (compatible) | Dye ink bottle, 70 mL | Cyan | 6,000 pages |
| Epson T502320 (compatible) | Dye ink bottle, 70 mL | Magenta | 6,000 pages |
| Epson T502420 (compatible) | Dye ink bottle, 70 mL | Yellow | 6,000 pages |
| Epson 502 Set of 4 (compatible) | Full bottle set | Black / Cyan / Magenta / Yellow | 7,500 black, 6,000 per color |
ET-3700 Ink: High-Volume Printer, Bottle-Priced Refills The ET-3700 is an EcoTank all-in-one aimed at busy households and small teams. Its tanks drink from the 502 family: T502120 black (127 mL pigment, up to 7,500 pages) and T502220 / T502320 / T502420 colors (70 mL dye, up to 6,000 pages each; ISO/IEC 24712, Epson methodology).
Because this printer tends to live in high-page-count homes, the 4-bottle set is the practical buy — it resets every tank in one order and keeps a color from stranding a print job. Singles are there when only one tank is low.
One caution: the ET-3700's name neighbors — ET-3710 and ET-3760 — are also 502 printers and share this page's ink, but the similar-sounding ET-4700/ET-4800 line is 522 territory. Badge first, bottle second.