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Dr. Gerd Meder*, Mohn media, 

Carl-Bertelsmann-Str. 161 M, 

33311 Gütersloh, Germany 

Dr.-Ing. Wilhelm Busse, 

Verein ZELLCHEMING e.V., 

Emilstr. 21, 

64283 Darmstadt, Germany 

Dipl.-Ing. Maik Coesfeld, Mohn media, 

Carl-Bertelsmann-Str. 161 M, 

33311 Gütersloh, Germany 

The ghosting printing problem in 

heatset web offset printing is understood 

as the reduction of the tonal values of 

the printout on one side, caused by a 

motif or colour combination pattern on 

the reverse. 

Das Papier Science and Technology 

Dr. Erich Frank, Flint Group Germany GmbH, 

Sieglestr. 25, 70469 Stuttgart, Germany 

Anne-Sopie Gombart, 

Sappi Netherlands Services B.V., 

Biesenweg 16, 

6211 AA Maasticht, Netherlands 

Dr. Joop van Hesteren, Solco NV, 

Zwaluwbeek14, 

9150 Kruibeke, Belgium 

Dr. Dirk Lawrenz, BASF Aktiengesellschaft, 

ED/PD – H 201, 67056 Ludwigshafen, Germany 

Ghosting is certainly the most irritating 

of known technical problems in heatset 

web offset printing. Depending on the 

angle of the rubber cylinder, the printed 

image on one side of a page will appear 

on the other side as a printing error – a 

Dr. rer.nat. Christian Naydowski, 

Voith Paper Holding GmbH & Co. KG, 

St. Pöltener Str. 43, 

89522 Heidenheim, Germany 

6/2008 

Peter Resch, Sappi Papier Holding GmbH, 

Brucker Str. 21, 8101 Gratkorn, Austria 

Dr. Joachim Schoelkopf, 

Omya Development AG, 

G. Meder, W. Busse, M. Coesfeld, E. Frank, A.-S. Gombart, 

J. van Hesteren, D. Lawrenz, C. Naydowski, P. Resch, and J. Schoelkopf 

P.O. Box 32, 4665 Oftringen, Switzerland 

*correspondence address: 

gerd.meder@bertelsmann.de 

Ghosting in Heatset Web Offset Printing (Part I) 

ghost image in effect. Fig. 1 exhibits a 

very good example of ghosting. The hair 

from the two women’s heads on the reverse 

leads to a brightening on the front 

(ghosting page). The name ghosting is 

very appropriate, not just because of the 

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6/2008 Science and Technology Das Papier 

Das Papier · Summary 

Ghosting in Heatset Web Offset 

Printing 

The ghosting printing problem will 

be examined on the basis of test 

samples and a test form (sample 

printouts and rubber blankets). It 

ghost-like reduction in tonal values, but 

also because of the apparently random 

ghostly occurrence of this effect. 

In the past a number of authors have examined 

this phenomenon and indicated 

the influence of various factors, such as 

paper, ink, fountain solution and rubber 

blanket 1-3 . The literature also mentions 

measures to reduce or even avoid ghosting, 

although every printer looking for 

Das Papier 2008–T57 

will be shown that the study of the 

deposits on the rubber blankets and 

the comparison with the deposits 

typical of the offset technique bring 

about a greater understanding of the 

phenomenon. 

help will find to his disgust that these 

recommendations often seem to contradict 

each other and are mostly ineffective. 

Even worse, a particular measure 

that was actually helpful with a specific 

ghosting problem proves to be ineffective 

with the next order when ghosting 

reoccurred. 

Fig. 2 presents a rough summary of the 

key parameters of the materials involved 

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in the printing process. An exhaustive 

scientific analysis would list a lot more 

parameters, however the key question is 

whether parameters can be named that 

have a major influence on the printing 

problem and that are significant in its 

resolution. 

Do we know too little about the mechanical, 

chemical and physical mechanisms 

that cause ghosting or is this problem 

too complex to allow one to expect a 

monocausal explanation between cause 

and effect? In fact, detailed studies of the 

ghosting phenomenon show that negative 

build-up, positive build-up, vanishing 

dots and ghosting are all interlinked and, 

in the final analysis, are simply different 

versions of the same basic problem 

with offset printing, depending on the 

parameters involved, namely the separation 

of the ink-water or water-ink emulsion 

between the rubber blanket and the 

paper. Adhesion and cohesion within

and between the relevant materials, their 

interplay and their dynamic modification 

by all the materials involved are the key 

to understanding the phenomena. 

For this reason, this paper will first consider 

in greater detail the deposits on the 

rubber blanket and the print copy in a 

specific example of ghosting. 

Fig. 3 demonstrates the side with the 

ghosting and the reverse of a print product. 

The percentage tonal values of the 

colours (black: S, cyan: C, magenta: M 

and yellow: Y) are specified for each 

section. The magenta triangles on the 

reverse appear as host images on the 

ghosting side. Fig. 4 reveals the magenta 

rubber blanket for the reverse, while 

Fig. 5 shows the magenta rubber blanket 

of the ghosting side. In both images the 

rubber blankets were photographed from 

different angles in order to make it clear 

which areas have the same deposits. 


In Fig. 6, areas with different colour 

combination pattern were defined in the 

printing of the ghosting side and reverse 

(back side). If these areas are compared 

with the magenta blanket on the ghosting 

page, it is noticeable that different deposits 

are detectable in the different areas. The 

deposits are clearly not just determined 

by the colour combination pattern on 

the ghosting side, but also on the reverse. 

The deposits in S1 and S3 are identical. 

The assignment of the magenta on the 

ghosting side is influenced in the same 

way by the major assignment of cyan on 

the reverse. Interestingly, the deposit in 

area G2 is changed by R1 (cyan reverse) 

and R2 (white reverse) – areas S1 and S2 

differ greatly. Even in area S4, where the 

white ghosting side (G3) lies directly on 

top of the cyan area of the reverse (R1) a 

difference from S5 is apparent. In S5 the 

reverse and ghosting side are white, in 

other words free of colour. If one looks 

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at the magenta triangle (S6), it is evident 

that there is a clear correspondence with 

S1 and S3. 

If we look at the print copy, Fig. 7, 

then it does indeed become evident that 

the ghosting triangle does not become 

brighter, but rather its surroundings become 

darker. Area G2 is darker in area 

R2 than in area R1. 

In Figs. 4 and 5 measuring points have 

been defined on the blankets and print 

copy at which the surfaces were enlarged 

(20 times to 200 times). 

Figs. 8-10 reflect the enlargements in 

and around the ghosting triangle (S6). 

They confirm the correspondence between 

the deposits at points 5 and 6 

(Fig. 5). The comparison of the dots 

in the print copy (Fig. 11) clearly indicates 

the larger magenta dots at point 8 

(Fig. 5). 

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If one examines the enlargement in the 

areas of the rubber blanket on the reverse 

(Fig. 12), it is possible to see the 

expected cyan dots at point 1 (cyan contact 

impression from paper on magenta 

rubber blanket) and the typical colouration 

of an ink-free surface at point 2. In 

the triangle itself (point 3) it is possible 

to see the clean surface of the rubber 

blanket – in other words there are no 

signs of a deposit or of colouration. 

Conclusion: different assignments of ink 

on the front and reverse of the print copies, 

and thus on the rubber blankets, lead 

to changes in tonal value. 

Examination of ghosting 

with a test form 

In order to move away from the more or 

less random assignment of colour on the 

print copies from ongoing production 

and to examine the question of changes 

in tonal value as a result of colour combination 

patterns on the front and reverse 

of a page, a test form has been developed, 

Fig. 13. 

Different colour combination patterns 

were arranged in this test form, both for 

the ghosting side and for the reverse. On 

the ghosting side, as well as the four individual 

colours, large areas of combined 

colour such as C20M20Y20 (tonal value 

in each case 20 % for cyan, magenta and 

yellow) were printed. On the reverse, 

the individual colours and colour combinations 

were arranged in a tile-shaped 

file formation so that increasing tonal 

values (20 %-100 %) occur in the various 

coloured areas on the ghosting side. 

For simplicity, the reverse with the tileshaped 

file formation will be referred 

to below as the tile side. In Fig. 13 the 

colour combinations used on both sides 

are indicated on the margins. 

The choice of colour combination pattern 

on the ghosting side and on the tile 

side makes it possible to examine the 

question which combinations of colour 

on the front and reverse or at which level 

of tonal values ghosting occurs. 

Fig. 14 presents the print copy (mirrored) 

and areas of the black, cyan and 

magenta rubber blankets after several 


thousand impressions. It is evident that 

the ghosting areas on the rubber blankets 

are much clearer and stronger than on 

the printed copies. This is particularly 

clear if printed copies are continuously 

gathered during printing – ghosting is 

time-dependent. Depending on the paper, 

ink, rubber blanket, etc. the ghosting 

can occur more quickly or more slowly. 

However the more it is rolled over, the 

stronger and more definite the effect. 

Fig. 15 displays a larger section of the 

magenta rubber blanket. Once again it is 

clear that the assignment of the colourfree 

area (to the right of the ghosting test 

fields) looks the same as the assignment 

of the tiles in which ghosting occurs on 

the print product. 

The blankets not only present the structures 

in their own colours, but also the 

structures from the previous blankets 

(Figs. 15, 16). Thus, there is direct ghosting 

(change in tonal value due to the 

interplay of the inks on the top side and 

underside in the same print unit) and an 

indirect, consecutive ghosting (change 

on tonal value due to the interplay of 

the inks on the top side and underside 

in different print units). The examination 

of direct and indirect ghosting will be 

discussed in a separate paper. This paper 

will further examine the structure on the 

rubber blankets (as the tonal values on 

the tiles increases). 

Fig. 17 shows the M20Y20 area of the 

ghosting side with the increasing tonal 

values of the tile side (MY20 – MY100). 

As the tonal value of the MY tile increases, 

ghosting becomes more marked, 

reaching its maximum between 60 % and 

80 % and decreasing slightly at 100 % 

(full tone). The 200 x enlargements of 

the relevant ghosting areas depict clearly 

formed dots at 20 %. As the tile tonal values 

increase, the full dot is continuously 

reduced to an ever-smaller, ring-shaped 

marginal area. 

If we look at the 200 x enlarged dots 

of the ghosting side (in and around the 

tile area on the reverse), Fig. 18, then 

the marked difference between the formation 

of the dots in the undisturbed 

area and in the area disturbed by the 

tiles is clearly visible. Figs. 19–21 show 

a 200 x / 400 x enlargement of the dots 


inside and outside the ghosting area. 

The mountain-like formation of the dots 

is remarkable. When the dots are separated, 

water and ink are obviously sucked 

in (a forced flow), causing this effect. 

If we look at the ink deposits on the 

rubber blankets in the areas of ink penetration 

and the areas free of ink, e. g. 

Fig. 12 or Fig. 15, we must interpret the 

ring-shaped edges of the dot in Fig. 19 

and Fig. 21 as areas of ink carrier. The 

areas inside and outside the ring display 

the typical deposits on areas without 

ink, i. e. these areas do not transfer ink 

or only transfer ink under certain conditions. 

The dot is increasingly narrowed 

both inside and outside by areas with no 

ink carrier. The sharp ring shape was not 

evident in all examined print samples, 

but the reduction of the external diameter 

was common to all samples. 

Until now it has not been possible to 

analyse the deposits clearly because, although 

it is possible to analyse deposits 

using secondary ion mass spectrometry 

(SIMS), the molecules are separated 

at atomic level due to the high energy 

primary oxygen ions and thus cannot be 

assigned to the original molecules of the 

ink particles. Naturally, such analyses 

contain particles of the paper coating as 

well as the particles of ink. However it 

seems unlikely that these are the cause 

of the build-up. It is more probable that, 

from a particular adhesion level of the 

ink particles onwards, particles are torn 

away from the paper coating. 

If the dots from the non-ghosting areas 

are compared with those from the ghosting 

areas (Fig. 21), it becomes evident 

that the dots of the non-ghosting areas 

within the dot area feature small areas 

that do not contribute to the transfer 

of ink. In contrast with the ring-shaped 

matrix dots of the ghosting area, however, 

this drop of ink can be equalized. 

Thus, the question is why, when ghosting 

occurs, parts of the dot surface change 

over from areas with ink carrier to areas 

without ink carrier as time progresses 

and why the dot gets smaller or even 

becomes ring-shaped. 

The behaviour of a drop of ink (or 

rather a drop of emulsion because the


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drop of ink is emulsified with the moistening 

agent – water and additive – during 

printing) under technical conditions 

has been examined by a number of 

authors 4-6 and has proven to be extremely 

complex. Technical marginal 

conditions to be taken into account in 

an analysis such as this include nip, accelerated 

separation, surface energies 

and water /oil depletion at the contact 

surfaces, formation of the meniscus, etc. 

We are unaware of a detailed analysis 

of whether, as a result of the dynamic 

stress on a drop of emulsion (dot), this 

can lead to physical-chemical separations, 

increased tack and the formation 

of areas with and without ink carrier or 

whether other mechanisms are responsible 

for the effects observed. 

Whatever the explanation, the question 

remains why the ratio of dots on the 

front in relation to the reverse is of 

decisive importance for the occurrence 

of ghosting. 

All enlargements indicate that the transfer 

of ink in the dot on the ghosting 

side is smaller. A lower transfer of ink 

means that the tack – in other words 

the force with which the drop of ink adheres 

to a rubber blanket and the paper 

– decreases. The size of the dot on the 

reverse remains unchanged. It is still 

necessary to examine whether the reduction 

in the dot diameter on the ghosting 

side is sufficient on its own to explain the 

difference in tack force and ghosting. 

Fig. 22 contains a schematic diagram 

describing which force components contribute 

to this tack. There is no doubt 

that different force components are relevant, 

depending on the distance between 

the separating surfaces. However the 

two main forces, namely cohesive force 

(separation within the drop of emulsion) 

and adhesive force (separation between 

emulsion drops and rubber blanket and 

paper) largely dictate what happens. Because 

the drop of emulsion is split between 

the rubber blanket and the paper 

when ink is transferred, the cohesive 

force is of decisive importance. What is 

the influence if it changes during printing? 

Upon what physical parameters 

does it depend? 


In 7 Keiter uses the laws of fluid dynamics 

to derive the separating force of a 

flowing material. The formula (Fig. 23) 

indicates that the force for separating a 

drop between two plates is proportionate 

to power 4 of the drop radius and 

inversely proportionate to power 3 of 

the ink drop thickness. There is a linear 

dependency on viscosity. 

It should be noted that the adhesion of 

ink (tack) and its viscosity are not identical, 

so that this formula can only be a 

good approximation. In particular, the 

viscosity does not record the fact that, 

while viscosity remains unchanged, the 

adhesive effect at the limits of the drop 

can change. 

Nonetheless, this formula shows the 

enormous influence of the size of the 

dot area – reducing this means greatly 

reducing the tack. 

Fig. 24 points out the influence of different 

dots and therefore tacks on the 

top and bottom sides of the paper web. 

If the rubber cylinder is arranged symmetrically 

and the dots are uniform in 

size, then the paper web is not deflected. 

If the upper dot is larger, it deflects the 

paper web to the upper cylinder, while 

if the lower dot is larger, it deflects the 

paper web to the lower cylinder. 

The upper and lower rubber cylinders in 

all heatset rotary print units are tilted 

towards each other to a certain extent. If 

the upper cylinder is placed behind the 

lower cylinder, looking along the paper 

path, this is referred to as a 1 o’clock 

setting, the other alternative being an 

11 o’clock setting. Fig. 25 explains the 

influence of different dot sizes with the 

two cylinder settings. 

It is important to note that ghosting 

occurs whenever the paper web becomes 

separated from the cylinder as a consequence 

of the different dot sizes and 

different tack. 

Because the different dot diameters on 

the top and bottom sides already exist 

at the start of printing, the process that 

finally leads to ghosting must be as follows: 

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1. Different tacks at the top and bottom 

cause the paper web to be deflected. The 

web adheres to the rubber cylinder on 

the reverse side to the ghosting side. The 

tensioning of the paper web pulls the web 

away from the cylinder. 

2. The deflection of the paper web causes 

the transfer of ink to the ghosting side 

(smaller dot) to be disrupted. 

3. The disruption to the transfer of ink 

leads to a change whereby the dot on the 

ghosting side is reduced. 

4. The reduction of the ink transferred in 

the dot causes a further increase in the 

difference in tack and thus leads to an 

increase in the deflection of the paper 

web. 

5. However, another effect must be added, 

namely, as a result of rolling over the 

dots, a change to the adhesion of the 

remaining emulsion or to the deposits 

on the rubber blanket on the tile side. If 

this were not the case, ghosting, which 

only occurs after a certain time with 

M20-K40 for example, would be immediately 

apparent with larger K values, 

e. g. M20-K60. However, the evaluation 

of the prints shows that this is not the 

case. In all tile fields the start of ghosting 

becomes apparent with the same number 

of rollovers. 

The process of reducing the dot on the 

ghosting side, changing the tack forces 

and separating the web each reinforce 

one another. As rollover increases, this 

leads to increasing ghosting. As a result 

of the tensile force of the paper web, the 

paper web again comes in contact with 

the cylinder – an effect also known as 

release doubling because, due to the 

deflection of the paper web, a misalignment 

occurs, so that a second image of 

the dots occurs at the second contact. 

Because the paper web is drawn back 

slightly as a result of the deflection, this 

mackling mark precedes the dot. 

Fig. 26 shows the development of ghosting 

for a dot directly in the ghosting field 

(dot 1) and a dot next to the ghosting 

field (dot 2) over time. The L/L0 value 

of the fixed ink combination ghosting


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side – tile side 20K-K60 or 40C-C60 was 

applied. While the L/L0 value for dot 1 

features a continuous rise, dot 2 remains 

practically constant. However, variations 

also occur in dot 1 – these can be so 

strong that ghosting actually disappears 

for a short time on some printed copies. 

Fig. 27 evinces different types of ghosting 

which occurred while testing many 

different papers but keeping all other 

parameters constant, such as ink, rubber 

blanket, etc. 

Fig. 28 points out the change in direct 

ghosting over time for the colour combinations 

20K-K, 40C-C; 20M-M as a 

function of the tonal value of the tile 

(L value over tonal value with the number 

of print copies as a parameter). Here 

again the variation over time can be 

seen. 

Interestingly, the formation of ghosting 

is not always constant across the scope 

and width of the cylinder. This demonstrates 

the evaluation of the ghosting 

effects (Fig. 29) of a test form (Fig. 30) 

in which the same test element was set 

up several times. Neither washing the 

rubber blanket nor changing the water 

feed altered the position of the maximum 

or minimum ghosting location. Not 

only the L value is different, but also 

the c value (chromaticity coordinate). 

Because the increase in the amount of 

ink (from 250 % to 300 %) has an influence, 

this indicates differences in the inkwater 

balance over scope and width. 

Ghosting only occurs (directly) when 

there are major differences in dot diameter 

or, more precisely, major differences 

in tack force – this can also mean 

comparing an area of solid colour with a 

dot area (Fig. 17). When dots are roughly 

the same (Fig. 31) a positive build-up 

and vanishing dot can occur. Even if 

there is only ink on one side, a vanishing 

dot can occur on this side and a negative 

build-up on the ink-free side. 


Unlike ghosting, these effects occur on 

both sides of the printed copy or rubber 

cylinder, but also have a preferred side 

here in relation to the strength of the 

formation, depending on the cylinder 

position. 

Fig. 32 displays an enlargement of a 

vanishing dot. With this phenomenon, 

ink builds up around the dot, causing 

the narrowing of the diameter and a loss 

of tonal value. This effect is particularly 

marked with tonal values from about 

40 % upwards. Unlike ghosting, in the 

case of the vanishing dot, a ring-shaped 

deposit occurs – compare Fig. 21 and 

Fig. 32. 

With very low tonal values (< 4 %), the 

build-up of ink around the dots becomes 

so great that a regular drop structure 

(orange-skin structure) occurs on the 

rubber blanket. Fig. 33 points out this 

effect. This rubber blanket once again 

clearly pictures the different deposits. 

The formulae in Figs. 22 and 23 also 

indicate why it is so hard to find a single 

measure to combat ghosting. The viscosity 

or tack of the ink (emulsion) and 

the topography and surface energies of 

the rubber blanket and paper surface 

influence the tack. More importantly, 

the capillary action and porosity of 

the paper, in other words the dynamic 

penetration of water and ink in the complex 

paper structure, change the emulsion 

drop decisively. 

The interplay of the inconsistent materials 

and variations involved in the 

process (printing) lead to many different 

interactions, Fig. 34. For this reason it 

should be understood that it was possible 

to minimize ghosting in concrete cases 

through the choice of a different paper, 

rubber blanket or ink, although a general 

solution could not be found. The future 

will show if detailed improvements in the 

materials and/or coordination of materials 

will enable ghosting to be prevented, 

or at least minimized, during printing. 


References 

1 Piette, P.; Lafaye, J.F.: Mechanical 

ghosting on web offset presses. Taga 

Proceedings (1989), 667-700 

2 Loibl, D.; Pöller, M.; Betzler, F.: Negativaufbauen 

im Rollenoffsetverfahren. 

Fogra Forschungsbericht Nr. 32.123; 

München, März 2002 

3 Reinius, H.; Rousu, S.; Marttila, J.; 

Nygard, S.; Rautkoski, H.; Pietila, H.: 

Mechanical ghosting in web offset 

– MAIN variables. Ink Maker (2004), 

No. 6, 30-36 

4 Behler, H.: Die Randstruktur von 

Druckpunkten – eine experimentelle 

Untersuchung der Farbspaltungsströmung. 

Dissertation 1993, TH Darmstadt 

5 Voß, C.: Analytische Modellierung, experimentelle 

Untersuchung und dreidimensionale 

Gitter-Boltzmann Simulation 

der quasistatischen und instabilen 

Farbspaltung. Dissertation 2002, Bergische 

Universität Gesamthochschule 

Wuppertal 

6 Brötz, H.: Ein Beitrag zur Farbübertragung 

in Nassoffsetfarbwerken unter 

besonderer Berücksichtigung des 

Feuchtmittels. Dissertation 1997, TH 

Darmstadt 

7 Keiter, S.: Haftung und Aufnahme von 

Druckfarben auf gestrichenen Papieroberflächen. 

Diplomarbeit 1998, Universität 

Dortmund


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