Hi NewDawn, I've never used the merge modes in DRAW. I have used them for layers in Photopaint so my comments actually apply to Photopaint. 1. The SUBTRACT merge mode is very bad news. The result of subtraction can be a negative number. For instance, (50, 150, 20) - (125, 125, 125) is equal to (-75, 25, -105). There is no standard for converting this to RGB numbers between 0 and 255.. Thus you never know what another program will do. 2. If you use the DIFFERENCE mode, you know that you will get (75, 25, 105). However, you may not get the color that you expect by thinking in color. 3. The ADD mode has its own problems. The result of adding those two number is (175, 275, 145). Again, I don't know of any standard to deal with 275. What number should 275 become. In general, I find it difficult to predict the final color of using merge modes. When I do use them, I will always merge the two layers before converting to another color space or saving the document. What color would you expect from subtracting gray from green. It's usually not what I would predict by thinking in color. I prefer the Lab mode for large changes in lightness and/or color. Lightness and color are not linked together in the Lab mode as in other color modes. When changing from one color space to another, I always combine layers with merge modes or layer masks. The arithmetic is done on a channel by channel basis. Most likely, the resultant colors are not the same when performing the arithmetic in Lab or sRGB. Phil
↧