Desired grade of gloss not attainable

Ink

Problem
1. Wrong ink system.
2. Insufficient ink transfer.

Solution
1. Use glossy ink.
2. Double print.

Cliche

Problem
1. Etching depth too shallow.
2. Wrong screen ruling.
3. Wrong cliche type.

Solution
1. Produce new cliche with greater etching depth.
2. Test new cliche with different fineness of halftone screen.
3. Use different cliche type.

Pad

Problem
1. Surface too rough.
2. Wrong shape.

Solution
1. Replace pad.
2. Use more tapered pad shape.

Substrate

Problem
1. Structure of material unsuitable.
2. Material unsuitable.

Solution
1. Structure of substrate influences result.
2. Ink looks matte due to stress cracks.

Other

Due to the thin layers of ink inherent in pad printing, it is generally not possible to attain as high a grade of
gloss as with screen printing.

Ink peels/flakes off substrate

Ink

Problem
1. Wrong ink system.
2. Wrong or no hardener.
3. Wrong/imprecise mixing proportions.

Solution
1. Only use ink system suited to substrate according to technical bulletin.
2. Corresponding hardener must be added to two component inks.
3. Weigh proportion of ink to hardener exactly.

Cliche

Pad

Problem
1. Oily pad surface.

Solution
1. Clean new pads with alcohol before use.

Substrate

Problem
1. Soiled surface (grease, oil, perspiration, mold release agents).

Solution
1. Pre-clean substrate with alcohol.

Other

Problem
1. Surface insufficiently or not at all pre-treated.
2. Curing (drying) time not observed.
3. Subsequent treatment of surface insufficient or lacking.

Solution
1. Check pre-treatment, repeat as needed.
2. Observe curing time as per technical bulletin.
3. Check subsequent treatment.

This Problem
frequently occurs because the type of plastic material is unknown, or unsuitable ink systems are
used. The requirements for adhesion and scratch proofing are very different due to the respective demands
placed on the finished products.
It is expressly recommended that the printing material be checked under the respective conditions of use
before printing any production run.

Motif smeared (smudged)

Ink

Problem
1. Too thin.
2. Too slow.

Solution
1. Use new ink.
2. Use faster thinner.

Cliche

Problem
1. Etching too deep.
2. Wrong screen ruling.
3. Wrong cliche type.

Solution
1. Produce new cliche with shallower etching depth.
2. Test new cliche with different fineness of halftone screen.
3. Use different cliche type.

Pad

Problem
1. Too soft.
2. Too little volume.
3. Prints over edges.
4. Stroke force on cliche and substrate not equal.

Solution
1. Use harder pad.
2. Use larger pad.
3. Correct head stroke.
4. Correct head stroke.

Substrate

Problem
1. Very irregular surface.
2. Surface not sufficiently precleaned.
3. Material not smudge free.

Solution
1. Use pad assembly or special pad.
2. Pre-clean surface.
3. Switch to different material.

Other

Problem
1. Jig not fastened tightly enough.
2. Jig unstable.
3. Jig not precisely made, object has too much play.
4. Cliche not doctored cleanly.

Solution
1. Tighten fixture.
2./3. Produce new jig.
4. Sharpen or change doctor blade.

This deficiency often occurs when thinner is added during printing run, where ink and thinner are not properly
mixed.

Small air bubbles (pinholes) visible

Ink

Problem
1. Too thick.

Solution
1. Add thinner.

Cliche

Problem
1. Poor etching.

Solution
1. Examine cliche with magnifying glass; produce new cliche as needed.

Pad

Problem
1. Surface damaged.
2. Wrong shape.
3. Too soft.

Solution
1. Replace pad.
2. Use more tapered pad shape.
3. Use harder pad.

Substrate

Problem
1. Statically charged.
2. Contaminated with dust particles.

Solution
1. Install ionizing unit.
2. Pre-clean. objects, if necessary, using air hose (air jet).

Other

Problem
1. Soiled artwork.
2. Dust present when films are copied.
3. Unclean environment, dust circulating in surrounding air.

Solution
1. Checks films.
2. Produce new cliche.
3. Dust particles, which appear to be air bubbles, can be transferred by pad from substrate to ink.

This deficiency can be contained easily. If bubbles always appear in same place, Problem
will be found in
cliche or pad. If position of bubbles shifts, Problem
is caused by dust particles or electrostatic charges.

Surfaces appear patchy

Ink

Problem
1. Too thin.
2. Wrong ink system.
3. Transparent ink.

Solution
1. Use new ink.
2. Use another pad printing ink.
3. Use opaque ink.

Cliche
Problem
1. Etching too shallow.
2. Wrong cliche type.
3. Wrong screen ruling.
4. Motif not slanted.
5. Different etching depth.

Solution
1. Produce new cliche with greater etching depth.
2. Use different cliche type.
3. Test new cliche with different fineness of halftone screen.
4. Slant motif.
5. Produce new cliche with constant etching depth.

Pad

Problem
1. Wrong shape.
2. Too soft.
3. Surface too rough.

Solution
1. Use more tapered pad shape.
2. Use harder pad.
3. Replace pad.

Substrate

Problem
1. Surface structure too irregular.
2. Soiled surface. olution

Solution
1. Use hard, pointed pad shape.
2. Pre-clean objects, e.g., with alcohol.

Other

Problem
1. Doctor blade sags.
2. Only printed once.

Solution
1. Use stronger doctor blade, or screen areas or slant lines.
2. Double print or preprint opaque ink.

This deficiency is easily observed in prints where peripheral areas are acceptable, but coverage (hiding) worsens
progressively toward center. See also “Insufficient Opacity.”

Fine lines converge

Ink

Problem
1. Too thin.
2. Too slow; ink smears.

Solution
1. Use new ink.
2. Use faster thinner and/or blow on pad.

Cliche

Problem
1. Etching too deep.
2. No graduated etching in fine motif.
3. Wrong cliche type.

Solution
1. Produce new cliche with shallower etching depth.
2. Only possible with strip steel/steel cliches.
3. Use different cliche type.

Pad

Problem
1. Surface too rough.
2. Wrong pad shape.
Solution
1. Replace pad.
2. Use more acute (more pointed) shape.

Substrate

Other

Problem
1. Head stroke set too deep.

Solution
1. Causes crushing; adjust head stroke.

This Problem
occurs with cliches having both a large surface and fine lines in one motif, because the surfaces
should be etched deeper and with screen, but the lines are to be etched flat and without screen.

Screen dots are (not) visible

Ink

Problem
1. Too thick.
2. Too thin.

Solution
1. Thick ink with fast thinner produces visible screen dots.
2. Thin ink with slow thinner (retarder) causes invisible screen dots.

Cliche

Problem
1. Etching too deep.
2. Wrong screen ruling.
3. Wrong cliche type.

Solution
1. Produce new cliche with shallower etching depth.
2. Depending on results desired, use finer screen for invisible screen dots or coarser screen for visible screen dots.
3. Use cliche type suited to screen type.

Pad

Problem
1. Surface too rough.
2. Wrong pad shape.

Solution
1. Replace pad.
2. Depending on results desired, use more tapered pad for visible screen dots or flatter pad for invisible screen dots.

Substrate

Problem
1. Surface too coarse/ very structured.

Solution
1. In this case, not the screen dots are visible, but the surface structure.

Other

Problem
1. Poor quality of artwork.

Solution
1. Check screen dot pattern on film or expose in new screen.

Screen dots are desirable for some prints, but not for others. Some photopolymer cliches cannot be produced
without a screen, or only with a certain type of screen. With steel cliches, the screen is only exposed in for
support of the doctor blade, to allow printing of larger motifs over an entire surface.

Splotches or spiderweb effect on contours

Ink

Problem
1. Too thick.
2. Ink build-up on pad.

Solution
1. Add thinner.
2. Use faster thinner.

Cliche

Problem
1. Etching too deep.
2. Wrong screen ruling.

Solution
1. Produce new cliche with shallower etching depth.
2. Produce new cliche with fine half-tone screen.

Pad

Problem
1. Wrong pad shape.
2. Surface too rough.

Solution
1. Use more tapered pad form.
2. Replace pad.

Substrate

Problem
1. Surface becomes charged with static electricity.

Solution
1. Install ionizing unit on printing press.

Other

Problem
1. Humidity too low.
2. Cycle time too fast.
3. Intermittent operation of machine.

Solution
1. Raise humidity to approx. 60 % – 80 %.
2. Reduce printing speed.
3. Regulate to constant cycle times.

Improvement can be achieved by grounding press. Splotches or spiderwebs most often occur with materials
such as polystyrene, polycarbonate, or acrylics.

Color of ink does not match artwork

Ink

Problem
1. Too thin.
2. Wrong ink system.
3. Wrong color match (in custom colors).
4.Transparent ink.
5. Shade cannot be mixed.

Solution
1. Use new ink.
2. Use pad printing inks.
3. Check proportions or re-mix as needed.
4. Use more opaque ink.
5. In this case no Solution
possible.Test another ink system.

Cliche

Problem
1. Wrong etching depth.
2. Wrong screen ruling.
3. Wrong type of cliche.

Solution
1. Check etching depth or produce new cliche as needed.
2. Test new cliche with different fineness of half tone screen.
3. Replace cliche.

Pad

Problem
1. Wrong pad shape.
2. Surface too rough.

Solution
1. Use hard, pointed pad.
2. Replace pad.

Substrate

Problem
1. Dark substrate color.
2. Changing material types.

Solution
1. Try to attain thicker ink deposit by double printing.
2. See below.

Other

Problem
1. Only printed once.

Solution
1. Test double or triple printing.

This Problem
occurs frequently in pad printing. It is, however, often impossible to achieve the original shade,
as it cannot be mixed from the colors available in pad printing. To lessen the influence of the substrate color,
the options are to: pre-print using white, double print, or triple print to increase the opacity. Each method
does, however, have its drawbacks, and should be tested beforehand.

Overprintability in multi color prints

Ink

Problem
1. Too thick.
2. Too slow.

Solution
1. Use new ink.
2. Use faster thinner.

Cliche

Problem
1. Too deep.
2. Wrong screen ruling.

Solution
1. Produce new cliche with shallower etching depth.
2. Test new cliche with different fineness of halftone screen.

Pad

Problem
1. Rough surface.

Solution
1. Replace pad.

Substrate

Problem
1. Very slick, dense material structure.

Solution
1. Substrates where surfaces cannot be dissolved by thinner are esp. problematic (e.g., glass).

Other

Problem
1. Insufficient pretreatment or subsequent treatment.

Solution
1. Heat objects before printing, or ventilate them for thinner to evaporate faster.

During high speed printing operations, the last ink printed may be removed by next pad. This occurs particularly
on larger surfaces, where material cannot be dissolved by thinner, or with slower inks in connection with
carree or rotary indexing tables and linear belts. The Problem
hardly ever arises when adjustable tables areused. The best Solution
is to pre-heat objects or dry them with cold or hot air at intervals during the printing run.