Sharp MX-5500N User Manual page 233

When the erase function is used, erase takes place at the edges of the original image. If you also use a reduction or an
enlargement setting, the erase width will change according to the selected ratio. For example, if the erase width setting is 1"
(20 mm) and the image is reduced to 50%, the erase width will be 1/2" (10 mm).
To cancel the erase setting...
Touch the [Cancel] key in the screen of step 3.
System Settings (Administrator): Erase Width Adjustment
The default erase width setting is linked to the copy mode system setting, and can be set from 0" to 1" (0 mm to 20 mm). The
factory default setting is 1/2" (10 mm).
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