Printing continuous forms
These prints are possible:
- All sheets printed equally in one or more colours;
- Only top sheet printed, middle and bottom sheets stay blank;
- Top sheet printed in 2 or more colours, middle and bottom sheets printed in 1 colour;
- Middle and bottom sheets printed differently;
- Print on the back of the sheets, usually with terms of delivery or other conditions;
- Middle and or bottom sheets printed with desensitizing ink, commonly used for price block out;
- Printing up to all four sides of the form.
Is used for printing continuous tone images and flat tints. Rasters can vary in lines per inch. The lpi values for continuous forms lie between 120 and 150 lpi. Higher values give much more detail in print, lower values means less detail. All depends on the printing press and the used paper.
The coverage of a raster area is indicated in percentages. Below you'll find a view of the colour process blue in steps of 10%.
When printing continuous forms we use a raster with 140 lines per inch. (55 lines per cm). A suitable coverage for flat tint areas is 5% to 20%. Please note that dot gain will occur and that heavy raster areas (> 30%) may adversely affect the imaging of the underlying parts of your form. Please consult us before you start designing.
For not depicting characters printed on the underlying sheets of a multipart form. For example a combined set of an invoice/packing form with no financial information visible on the packing sheet.
There are two solutions for block out:
- A heavy grid pattern in a random shape, printed in black or another dark colour;
- Transparent desensitizing ink. This ink layer is (partially) printed on the front coating of the carbonless paper so that there is no chemical reaction with the sheet above.
Rich black in full-colour print
If you have large black areas, a value of 50% cyan and 100% black will suffice and gives a nice deep black colour. Rich black is not suitable for small text and thin lines since this can lead to registration inaccuracies.
Maximum ink limit at full-colour continuous forms
The ink limit is the sum of all 4-colour channels in the CMYK colour space ( theoretical 4 channels x 100% = 400%). For continuous forms, the maximum ink limit of these channels may not exceed the value of 260%. This value prevents unwanted transfer of the ink in the delivery. This can be accomplished by conversion to the colour profile, ISOuncoated_vigc_47L_260
Maximum surface coverage for full-colour continuous forms
The total area that can be printed in full-colour is between 15 and 20% of the NET format.