Roland GR-640 User Manual page 207

Align the right edge of the material with the front
and back gradations of the platen.
Select the type of material.
Using Various Types of Materials
Press [ENTER].
The pinch rolls lower and the carriage and material move.
When the movement is finished, the cuttable width and length are displayed.
Use [ ] and [ ] to move the material and position
the crop marks above the blade protector.
(1) Blade protector
(2) Crop marks