The 'Default Paper Size' can be used to define a cost for any paper size not already explicitly configured in a Job Cost Method.
When defining a Job Cost Method, the 'Per Page Attribute Costs' allow defining individual costs for different paper size/attribute combinations such as "Letter, Color" costs or "Letter, Duplex, Color" costs. If a user submitted a job with a paper size that did not match the paper sizes defined within the Job Cost Method, they would be charged the value defined in the 'Default Per Page Cost' property of the Job Cost Method. However, this cost would be the same regardless of any other job attributes such as 'color' or 'duplex'. As of Service Pack 1, it is possible to define a series of attribute-specific costs for the 'Default Paper Size'.
For example, a color job submitted as Folio size can now be charged a defined color cost, rather than just a single default cost; a color/duplex/folio job can now be charged a defined color-duplex cost.
To configure Default Paper Size costs:
Any cost defined in the 'Default Per Page Cost' property will now be overridden if values for the Default Paper Size are defined within the Per Page Attribute dialog, except in the case where a zero value is given for a 'Default Paper Size' attribute combination.