HP 400 - Manual (Page 79)

5-16 Problem Resolution
Avoiding Print Skew
Print skew results when the movement of paper in the mechanism is not square to the carriage
movement. The result is inconsistent print margins along the paper’s edge.
• Print skew is determined by three elements:
– The printer itself may skew paper that is otherwise within specification and loaded correctly.
– The paper may not be square.
– The paper may not be properly loaded.
• The squareness of the paper can be measured (see below). Any paper skew will be added to or
subtracted from the print skew attributable to the printer itself, resulting in a “total print skew.”
• Total print skew can be measured by the procedure described on the next page. From the total print
skew you can subtract the paper skew to determine whether the print skew attributable to the
printer itself is within acceptable tolerances.
• It is possible to reduce total print skew by proper loading and handling of the paper. Review the
instructions included with the user documentation to ensure that the paper was properly loaded.
Printer Skew Specification
The print skew specification for HP DeskJet 400 printer is no more than 0.006 inches per inch on 95% of
all pages printed. The squareness of the paper and how paper is loaded can also add to total print skew.
Pre-printed forms with their own printing
already skewed can increase the apparent print skew if the
form is skewed in the direction opposite from the printer's skew. Any skew on the printed form must be
taken into account when measuring print skew.
Measuring Paper Squareness
Total print skew may be affected by the squareness of the paper. The industry standard for paper
squareness is no more than 0.003 inches per inch. This tolerance must be added to the printer’s own print
skew specification to obtain a true total print skew specification. Test the paper squareness by printing on
one side of the paper, flipping the paper over, then printing on the other side. If the print slopes down on
one side and up on the other side, the squareness of the paper may be affecting the total print skew. In
this case, you may be able to reduce the total print skew by trying a different kind or brand of paper.
Note When using the paper tray, always load a stack of paper into an empty IN tray rather than placing
paper on top of paper
already in the IN tray.