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Digital Printing FAQ's

Help & Advise - Printer Frequently discussed printer related topics

Banding during printing

Generally the printer should print slower for high quality prints when it is outputting more ink and faster for lower quality prints when less ink is being used.

Consistant horizontal banding is something that may appear when printing areas of solid colour if the ink is being put down too fast for it to dry adequately before the next print pass. The result is the overlap of ink on the subsequent bi-directional pass forming the banding.

To alliviate this effect either use a slower print speed or re-print using a setting that uses less ink or switch to printing in a uni-directional mode. Check that the correct profile is being used.

Wider horizontal banding issues more commonly seen at the edges of the roll (or may appear as a watermark) can be caused when the roll of media has been stored on it's side instead of being stored vertically on end or when the roll has been rested on the printers feeder rollers overnight.

Very narrow horizontal banding (may also appear as fuzzy text) may be the result of innaccurate printer nozzle alignment and the nozzle cleaning function should be performed until a solid colour is acheived.

Vertical banding in the print is the result of variable ink saturation and it is important to make sure that the heaters are working correctly and that the heater settings are set to the right temperature. Too hot and some media will ripple, too cool and the ink will not dry.

Banner material doesn't feed properly

This is often due to the weight of the material roll causing too much resistance against the friction feed of the printer.

To overcome this issue, which is more of a problem with some older printers we offer to rewind down 50m rolls to 2 rolls of 25m at no extra cost. If this is not practical you can overcome this by manually unwinding the required amount so that it feeds into the printer without resistance.

Blurred image

Check the original image file to make sure that the quality if high enough for it to be printed at a high resolution.

Colours appear washed out

When printing onto transparent or translucent media for window graphics and backlit signs the colours can looked washed out. The best way to overcome this is to overprint the graphics again so doubling up on the amount of ink and colour depth.

Edge curl after print & cut

This can be a problem on self adhesive materials if it is contour cut straight after printing especially in darker coloured areas where there is the most ink output as the retained solvent from the ink causes the vinyl to soften.

Either select a thicker vinyl such as Xerox D-Jet 100 or D-Jet 200 as these have a heavier face film and this reduces the likelihood of lifting or allow 24 hours for the ink to dry before countour cutting.

Do not cut into the printed image as heavy concentrations of eco solvent ink will contribute to shrinkage and edge curl. Instead leave a 5mm border around the image and always conduct a suitability test.

Flecks appearing in the print

This is caused by dust or debris contamination from the print room environment. The inks tends to either accumulate around this settled debris and so appears as a dark fleck or disperses around the debris and appears as an unprinted white dot. Either way it is important to clean the area thoroughly and dry wipe the roll using a clean lint free cloth before trying again.

Image appears pixelated or blurred

The reason for this is generally the quality of the original file source or the editing of the file. It is important to ensure that the resolution of the original file is of a quality high enough to give satisfactory results.

Ink pooling during printing

Caused when too much ink is put down by the printer and shows up as damp looking areas of colour and is especially noticable on gloss surfaces. Check that the correct profile has been used and that the heaters are functioning properly. Also, make sure that the roll of media is at room temperature as cold rolls can exagerate the issue.

Laminating Film Problems

It is important to wait 48 hours before laminating your prints to allow the solvents in the inks to gas off. Failure to do this may result in excessive laminate shrinkage or delamination as excess solvents can break down the adhesive structure. Note that some pale colours may look different when laminated but there is no way around this.

Uneven colour when printing

More apparent when printing light pastel colours, the effect being a slight noticeable difference of colour across the width of the roll. The easiest way to prevent this happenning is to print using the uni-directional mode.

Vinyl not releasing from its backing liner

It is sometimes easy to assume that the application tape is too low tack to remove the cut and weeded text / graphics however this rarely the case.

More often than not the reason for this problem comes down to excessive cutting blade pressure, which scores into the backing liner. The best way of checking is by peeling back some cut graphics and checking that the blade has only just marked the backing liner and that there is no scoring into the liner. Now check the reverse of the backing liner to check there are no visible impressions of the cut path coming through. If this is visible you need to reduce the cutting pressure incrementally and produce a number of test cuts to acheive the optimum pressure. Once this has been done the graphics should lift away easily.

The best method of removal instead of pulling the application tape away from the surface of the graphics is to turn the graphics over and remove the backing liner away from the adhesive side.

Please note that each type of material will require you to perform this test cut routine to ensure optimum cutting pressure. Thicker materials such as fluorescents and reflectives as well as some polyester films generally require greater pressure than standard vinyls while thinner materials such as cast vinyls will require less pressure. It may also be neccessary to change the cutting blade for one with a greater angle for sandblast vinyls, reflectives and fluorescents as well as flock materials.

Vinyl peeling, cracking or edge lifting

The most important factor here is selecting the most suitable film for the job and remembering that although cast vinyl can be worked into channels and recesses as well as around compound curves using heat calenderd vinyl should applied onto these areas without putting the film under any stress.

It is important to promote the initial adhesive contact to ensure that graphics do not lift or peel. Surfaces should be cleaned, dried and wiped with Isopropyl alcohol before any graphics are applied. In cold conditions it is best to apply heat after application to further enhance the bond.

When applying lettering to the sides of tankers and other vehicles transporting aggresive liquids such as fuel or solvents we advise that the edges should be sealed with a protective varnish.

Vinyl tunnelling or rippling

This is noticable at the point of printing when the vinyl ripples or seperates from the liner and a 'tunnel' appears at the edge of the roll and works its way towards the centre of the roll. It is caused by the heat of the printer being set too high, often done to speed up the ink drying process. This excess heat caused the face film to expand on the relase liner resulting in delamination.

Watermark appears during printing

This effect is noticed towards each end of the media roll and may be due to the fact that the roll has been left resting on the printers feeder rollers for some time, perhaps overnight. The weight of the roll resting on the support rollers for this long period causes pressure through the roll and when printed the uneven surface causes this random effect. When not in use the rolls of media should be stored vertically on end or in a properly supportive carton as this can cause the same effect.

Call us on 01858 431642 , we're always happy to help!

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