Offset Poster Printing is based on a chromatic mode subtraction - with the CMYK primary colors Cyan, Magenta, Yellow and Black color. Here, ambient light is partially reflected on the surface of the object which we perceive to ammene different color impressions. Subtracted surface in this case part of the light, so that we see different colors depending color mode applied. The two color modes found in the color spectrum visible to the human eye, in two different places, cover only part of the same colors, and for this conversion from color to RGB color mode (smaller) CMYK often leads to differences in color rendering.
If we prepare our files in the (poor) RGB color mode, we can already expect two unwanted effects which are: the colors do not come out as bright as a light support, such as eg PC screen . and the conversion may alter the color. With these two effects we can add the influence of the type of paper on the printed record that also restores the color in his way (offset paper absorbs more ink, thus marginally darker, or a coated paper that reflects a little more light ...) and this can end in a rather frustrating.
