User`s manual

Printing on Special Paper
0.12 inch
(3mm) minimum 1
0.87 inch
(22.0 mm) minimum
Note: Envelope printing is only available at normal temperature
(40°F to 95°F or 5°C to 35°C).
To make sure that the printing fits within the printable area, always
print a test sample using a normal sheet of paper before printing on
envelopes.
2-30 Paper Handling