HP 2566C - Manual (Page 111)

In order to ensure satisfactory print quality on all areas of the form, the
difference in thickness between the thickest and thinnest section of the
form should be no more than .008 inch (as shown in Figure B-2). The
print gap should be adjusted to optimize print quality on all thicknesses
of the form.
Since dot-matrix printing is optimized when printing at one gap size,
print quality can, in some cases, be compromised when printing on
forms of varying thickness. This is especially true on the copy sheets
of multi-part forms. When printing on forms of varying thickness, the
maximum depth of depression defects on the thick part of the form is
also .008 inch.
Case 2: Varying Thickness Forms: Printing on Aii Areas.
Case 3: >^rying Thickness Forms: Printing on Thin Areas
In order to avoid smearing on the thickest area of the form when
printing on the thin area only, the difference in thickness between
the thinnest area and the thickest should be no more than as shown
in Figure B-3 (.015-T/2; T=thickness) inch. For forms with larger
variations in thickness, the print gap may he opened beyond the
optimum gap to reduce smearing, but print quality on the thinner areas
will degrade accordingly.
Figure B-3. Maximum Thickness Variation for the Thin Areas of a Special Form
B-4 PAPER SPECIFICATIONS