There are certain variables that can affect components during production and though on their own they can be small, they can combine to affect the final cover design on the trimmed book. By following the advice detailed below you can remove any potential problems pre-printing.
Maximum ink coverage
Ink that is not dry can be transferred to the for-edge of the books when trimmed in the bindery. Ink that is not cured can flake off the board, including any finishes on top, i.e. foil and varnish. With large areas, the adhesion of the laminate can also be affected, and UV varnish can give a mottled effect. Maximum ink coverage should not therefore exceed 350%.
Ink takes longer to dry on uncoated board (including the reverse side of coated stock), so for these designs, the ink coverage should be limited to 240% in total. Again, this will minimise any chance of drying issues or marking.
Printing on Wibalin cloth
Metallic colours on solid printed endpapers
Uncoated cover board
Ink coverage: Ink takes longer to dry on uncoated board (including the reverse side of coated stock), so for these designs, the ink coverage should be limited to 230% in total. This will minimise drying issues or marking.
Foiling: When foiling on unfinished cover board/jacket paper we need to use the HC foil grade. This foil is thicker than our standard foil which enables us to apply additional heat and pressure to ensure the foil reaches the bottom of the grain and transfers successfully.
Spot UV: We would not recommend applying spot UV onto unfinished cover/jacket paper as because of the absorbency of these substrates, the finish of the spot UV is often quite dull and patchy. This finish will therefore be at the customer’s risk.
Printing over foil - Design recommendations
- Avoid areas with a tight fit between blocking and printing.
- Avoid small areas of foiling and over-printing as there is an indentation made on the sheet at foiling stage which is then difficult to over-print.
- Sheet distortion takes place in both processes so fit can vary between foiling and over-printing. This is more noticeable on the back edge of the sheet.
- Always laminate job to ensure ink doesn’t scratch off foil.
Hard “scuff free” matt lamination
Pile, glitter textured and matt spot varnish
Glitter spot varnish is increasingly popular and although other colours are available on request, we currently stock gold, silver and crystalina. Two particle sizes are used, 004 and 008 and can be used on their own or mixed. Further information is available on request.
For all of these finishes, the following guidelines should be followed:
- These types of varnish should not be positioned over folded, creased or trimmed areas.
- Another varnish (i.e. glitter) cannot be applied over the top of the varnish. It cannot be embossed as it will crack and “flake off”.
- Glitter varnish with large solid areas of cover will take longer to produce and so could require a longer schedule.
- As with normal spot varnish, glitter spot varnish will soak into an uncoated board such as Colorplan and the “glitter” will then flake off. The way around this is to clear foil the areas first, and then glitter varnish over the top.
Card tip-in at front, back or both of book, with inside cover printing
For this design, the following guidelines should be followed
- The image must bleed 2mm into spine on inside front OR inside back cover. This should help to avoid white line between cover and tip.
- 2pp card tip: no finish (i.e. varnish) to appear within 3mm unsewn allowance and 3mm in trimmed back (i.e. 6mm unfinished strip in total) to facilitate binding.
- Cover finish on inside printing: no finish (i.e. varnish) to appear within 3mm of spine on inside front cover or inside back cover as applicable to facilitate binding.
It is important that stickers feed off the reel feet first in order to avoid hand stickering.
- label spacing should be a minimum of 2mm
- reel width should be 290mm
- we can accept reel width of less than 290mm but please make as wide as possible
- reel core is 44mm
- label width is 6-55mm
- label depth is 12-40mm
- there is a 1mm tolerance when placing stickers
- stickers per reel
- please supply as many stickers per reel as possible, for example, if there are 6000 stickers supply as 1 reel of 6000 stickers rather than 2 reels of 3000 stickers
Round and Backed / Flat backed
Covers with Flaps
The production method for this style of binding entails two runs through the binding line. Due to this process, we achieve a much cleaner and stronger final binding result if we side glue the covers.
Webroom – Text printing
Halftone printing on text paper
At Clays we use cold set web presses, where, typically, mechanical dot gain on the printing press will be in the region of 22% (industry standard). To avoid the shadow (dark) areas of your illustrations printing unacceptably dark, the maximum dot size on your data should be no greater than 80%, conversely the highlight (light) areas should be no less than 7%.
Choice of paper plays a major role in determining the quality of the printed result. A significant contributor to dot gain is the dust on the surface of the paper, which allows the ink to spread or the dot shape to change. A good quality dust free paper will provide a far superior result compared to a dusty paper. If you need help with choosing an appropriate paper, please contact your account controller.
Wherever possible, halftones should be avoided in the first or last sections of the book (1st 32pp or last 32pp) as a certain amount of “set-off” (i.e. ink transferring onto the page facing the halftone) is inevitable due to the binding process. This will be particularly noticeable on hardback titles, if the illustration or tint is particularly dark or if the illustration is facing the title page or a blank page.
If you have a title where positioning of halftones on these pages is unavoidable, please contact your account controller to discuss.
If the subject is a series of tint blocks (a bar chart for example), the tints should be a minimum of 7% going up in steps of no less than 10% (to ensure definition) to a maximum of 70%.
Halftone images should be supplied without a screen ruling. Clays will apply the screen ruling of 150 lines per inch for illustrations printed on text paper and 175 lines per inch for illustrations printed on separate, coated paper.
Creating a “stencilled” image on edge through bleeding fore-edge printing
Our guidelines are a minimum of a 6mm ‘tab’ image on the fore-edge – 3mm inside and 3mm outside of the trim.