Epson printers support plain paper and a wide range of genuine Epson paper and special media. Before choosing an envelope to print on, you should determine what weight the printer can support and the supported paper types. The user's guide supplied with your Epson product lists the Epson paper types and envelope sizes suitable for use with your printer model (see the 'Product Information' or 'Paper Handling' sections). The user's guide is also available in your product's Online Support and Manuals section on the Epson Support website.
The most common supported sizes for an Epson inkjet printer are:
Envelope No 10 = 4⅛ x 9½ in.
Envelope DL = 110 x 220 mm.
Envelope C6 = 114 x 162 mm.
Envelope C4 = 229 x 324 mm (A3+ printers only).
Epson A4 printer models do not support C4/A4 size envelopes. The C4/A4 envelopes are too large for the width of the paper feed and may damage the paper feed mechanism.