In order to consistently receive high-quality prints, you need to have a good understanding of the hiding power of inks and be able to apply them.
Opacity – the ability of ink to overlap the color of the product (the color of the previously printed ink). As a rule, the covering power depends on the amount of pigment, the composition of the base ink, and in relation to the print, also depends on the layer thickness (including viscosity, as it affects the layer thickness). For all these questions, you can consult your ink supplier.
Imagine that we have printed a red rectangle on a white sheet of paper. Over it we will print a yellow rectangle. You can see both of these rectangles in the figures below.
If we use transparent inks when printing, the result of applying the colors will be as in the figure below. The more transparent the paint, the stronger the previous color is visible through it.
- Note! Notice how the composite color changes when the order of the overlapping colors changes.
You can adjust the opacity in the channels, for this you need to double click on the picture of the channel and you will see a menu where the percentage indicates the opacity of the selected channel.
Conventionally, all the values of the covering power of the paint to adjust the channel can be divided into 4 categories. Here, the decisive criterion we chose to print on black.
- 10-20% – transparent paints similar to the triad CMYK in covering power. When printing such a paint on a black print is almost imperceptible.
- 20-40% – semi-covering inks. When printing on black print is visible, but the color varies greatly.
- 40-70% – covering inks. When printing on black, it retains the recognition of color, but to fully match the color, it is necessary to print 2 times with drying.
- 70-100% – the press in 2 passes with drying the covering paint.
Values within the specified ranges may depend on the pressure force during printing, the hardness of the doctor blade, the inclination of the blade. By default, all color channels are generated with 10% opacity.
- Note! Immediately after generating the channel, set the required level of opacity depending on which ink you will use when printing.
- Note! The recommended opacity value for the black halftone channel is no more than 10% (by default). This corresponds to black from the CMYK set.
- Note! The mesh for raster black should also be selected either at a higher number or at a lower bandwidth in order to minimize the effect of distortion when spreading.
Opacity and Pantone video
Pantone is a standardized color matching system. There are a number of color sample catalogs, each designed for its own printing conditions. Therefore, color swatches may vary. Color numbering for color separation for silk-screen printing is usually used for ease of adjustment during printing.
Since the Pantone color space is different from the RGB color space, it is not always possible to pick up a completely identical color Pantone pattern corresponding to RGB.
- Note! In the final assignment of colors to the channels, we recommend to have in front of you (in physical paper version) the same set of Pantone samples that will be used for printing.
- Note! We also recommend that when printing halftone images with marks, leave small spot squares for color control. Often, in halftone images there are no solid areas from which you can see exactly what color is printed. And as you know, the color of transparent paints can be very different on the stencil and on the print.