Four aspects can test whether a film quality reach the standard: (Shenzhen printing factory)
A field density, and the fog, it is the basis to evaluate the quality of the film. Fog is refers to the absolute density of blank film, the upcoming densitometer absolute zero (the air cleared) measured the density of blank film, the fog value = 0.03 film is excellent, 0.03 to 0.07 are qualified. So-called field density is defined as the value of the density of large solid block, general publishing software comes with ash wedges because the area is too small, plus some Yaomo film trachoma, which actually density measurement value than the actual value is much smaller, generally between 3.5-3.8 is qualified, but if large field must ensure that its density values between the 4.04.3 to assurance printed color saturation and does not make the darkened levels Union.
A value of two, linear, it is a major factor in the amount of film quality. General should ensure that the film gray scale, the mark of numerical and measurement is less than 2 for qualified. But due to the high precision printing machine has a certain color adjustable degree, so as long as we ensure the linearized difference is less than or equal to 5 that can guarantee the quality of printing products.
Three, dot dot shapes, screen angle and hanging wire number, network requires smooth, substantial, there is no sawtooth, no tail; network angle in accordance with the standard (generally monochromatic 45 degrees, four-color to difference is about 30 degrees), do not hit the net; hanging cable number suitable for printing medium (such as news paper is not higher than 120lpi, coated paper not less than 133lpi).
Four, after the exposure of the film quality, is the last one off, but also the most likely to be a factor ignored. The film on the field without trachoma, membrane no scratch, no oil, no point fixing without removing the "". Can be said to be a good quality film.
