Patent ID: 7836826

Claim:
A dampening water control method for controlling a feed rate of dampening water by using a dampening water regulating scale, comprising: a platemaking step for making a printing plate having a first detecting patch including lines or dots and having at least 200 lines per inch and an area ratio of at least 60%, and a second detecting patch including lines or dots and having a smaller number of lines per inch and a larger area ratio than said first detecting patch; a test printing step for printing a test image with the printing plate and with dampening water supplied at a proper feed rate; a confirming step for confirming a combination of an area ratio of said first detecting patch and an area ratio of said second detecting patch that causes a density of a portion of the test image corresponding to said first detecting patch to be substantially the same as a density of a portion of the test image corresponding to said second detecting patch; a printing step for printing, along with an actual subject image, images of said first detecting patch and said second detecting patch having the area ratios confirmed in said confirming step; and increasing a feed rate of dampening water based on relative densities when a density of the image of the first detecting patch is greater than the density of the second detecting patch.