op.em

inserts spaces in output text and is dependent on the printer type.

'number.spaces' is a spatial insertion parameter and has set possible values (0,1,2...). This is used for exact spatial alignment on LASER printers.

'.em number.spaces' inserts a 'number.spaces-to-the-em' space. One 'em' equals the width of the space character, i.e., '1-to-the-em' is one space character, '2-to-the-em' is one-half of a space character, and '0-to-the-em' is one-tenth of a space character.

The effect this command has on the output text is dependent upon the type of printer being used.