Having the stack at the end of may according to the formula, any color and K100, as a result of CMY color value is the background color, k-100. in this way, black text layer can not knock-out.

• 正片叠底，根据公式可以得不入，任何色与K100纯，爆发的甘休色为CMY值为底色色值，K为100.；这样，不不白色笔墨图层不离可以不镂空了。