Pentax PocketJet 3 - Manual (Page 41)

Left Margin:
This setting can modify the left margin when the ‘Custom’ ‘Page
Size’ is selected. You may choose to avoid any changes by
selecting ‘Use Paper Size’ which will assume you wish to use
the full 8” available print width. You may also choose to set a
number of columns of unprinted left margin. The actual
empty width created will depend upon the current character
pitch as set by ‘Default Pitch’. For example, if the default pitch
is set to 12 characters per inch, and you set the right margin to
‘9’, there will be a 3/4” (9 x 1/12”) right margin established. If
the current ‘Default Pitch’ is set to ‘Proportional’, 10 characters
per inch pitch is used for this calculation. Values that cause
up to 4.5” of left margin are allowed.
Page 31