DE3322763A1 - Achromatic test configuration - Google Patents

Abstract

Published without abstract.

Description

Achromatic test form

The invention relates to a test form for determining the addition of chromatic colors (BA) for achromatic color sets in multicolor printing. It is characterized by that: 1.) the same motif is present in several stages of the BA and / or 2.) Geometric test areas that are covered with the full printing ink black, are available in several stages of chromatic addition, whereby 3.) also conventional Composed color sets of the same motif (chromatic composition) available for comparison and 4.) the evaluation can be carried out both visually and by measurement can.

The achromatic image structure in multicolor printing is based on an idea of the inventor attributed for the first time in 1976 in the book "The Logic of Color" (Callwey Verlag, Munich) was published. In his book "DuMont's Color Atlas", the inventor (DuMont Buchverlag, Cologne, 1978) demonstrated that the idea of achromatic image structure can be practically realized.

The conception of the achromatic picture structure says that it is in multicolor printing Technologically and economically it makes sense to use all achromatic values in the entire multicolored To create an image in principle by using the printing color black. In the previous As is well known, the achromatic values are created in principle in "conventional" multi-color printing from subsets of the three colored printing inks.

With the optimal achromatic composition, the black image depth only lies the full layer of black printing ink alone.

In practice, however, this conception can only be used under very special conditions Realize circumstances optimally, namely only if optimally suitable printing materials and printing inks are available. With good art paper and a special one The perfect achromatic structure can be realized with the printing ink "achromatic black".

The achromatic structure can also be realized if the full Black ink layer alone on the substrate does not have the desired blackening, thus brings the required density. In this case, subsets of colored printing inks must be used can be added to the black to achieve the required color density.

This adding, adding, is represented by the term "chromatic addition" (BA).

The invention is a Te ^ stf-heat, with which the required or the desired addition of chromatic colors can be determined. The test form gives the Possibility for a very specific material combination, i.e. for a substrate-printing ink combination, to determine the desired and required addition of chromatic colors in order to achieve the advantages of the achromatic image structure can be used as far as possible.

With the help of the test form according to the invention it is possible either by visual comparison or by density measurement the desired or required To determine BA.

The same image motifs are shown several times in the test form. The different Versions of the same motif differ in that the neutral Added different levels of BA to dark tones and black shadows have been.

For example, a picture motif can be used in the test form in the following six BA levels be available: 0%, 10%, 20%, 30%, 40%, 50%.

Is such a test form e.g. from a printer with the to be used Edition color on the edition paper to be used in the printing machine to be used printed, then he can create the optimal addition of chromatic colors for this individual material-printing machine combination determine.

If this example shows that the levels 0%, 10% and 20% If BA is too "thin", i.e. it looks too gray and has too little gloss, then the BA value is too low in these levels.

On the other hand, it turns out that the levels 30%, 40% and 50% BA all three have the desired density, then it is shown that the level 30% BA is optimal for this paper-printing ink combination. Because a higher value BA leads no longer leads to a greater visual blackening.

In principle, however, the required BA can also be determined using test fields. Surface areas which are covered by the full layer of black printing ink, is added in stages of chromatic color addition. The visual evaluation is then possible according to the same conception just described.

The evaluation can, however, be used for both image motifs and test areas also take place by measurement. It then becomes the black image depths or the test areas measured densitometrically.

In this way it can be determined by means of densitometric measurement, at which chromatic color addition the required density value is reached.

The test form can consist of a single picture motif or of several picture motifs exist. It can consist of test areas. But you can also use test areas and motifs exist.

The same motif can also be used for comparison in the conventional Image structure must be present in the test form. This gives the interesting opportunity visually and metrologically the image depth of the conventional image structure with the achromatic to compare built-up multi-color sets.

The reproduction of the image motifs and the test areas of this test form can be created either through halftone printing or through real halftones.

The test form according to the invention has the following advantages: 1.) For certain Material combinations (e.g. for certain edition papers in connection with certain Edition color) the optimal BA can be determined.

2.) Under certain printing conditions (e.g. for a certain printing press or for a defined layer thickness of the applied black color layer) the optimal BA can be determined.

3.) The evaluation of the test results can be visual as well take place metrologically.

Claims (7)

Claims: Test form for determining the addition of chromatic colors (BA) for achromatic image structure in multicolor printing, characterized in that: The test form can consist of an image that is present several times in different levels of the BA is. 2.) The test form can consist of several motifs, each are present several times at different levels of the BA. 3.) The test form can consist of test areas with the full Color layer of the printing ink black are covered and in which also several BA levels are available. 4.) The test form from a combination between 1 and 2 on the one hand and 3 on the other hand. 5.) The test form is created through reproduction in halftone printing. 6.) The test form is created through reproduction with real halftones. 7.) Test form according to claims 1 to 6, but where for comparison the relevant achromatic image motifs or test areas also in conventional Color composition are available.