Published 2020-07-05Carol E. Leever
In the previous blog I mentioned that you can take a grayscale image, add a COLOR blending mode to it, and quickly add color to the image without affecting the values. But you can also do the reverse.
Let say you started a painting, got all your values perfect, then added your color. Then merged everything together and continued painting. You are hours into your painting, and you've been adding all sorts of new colors and more layers to it. Then you start to notice that something just isn't working anymore. Your values are all wrong after all the new stuff you've added.
Colors are complicated, and it's very easy to lose track of your values. Maybe the red you added to something was too dark, and you should have used a color with a much lighter value.
There are several different ways of converting your painting briefly back to Black and White to check on your values without losing your colors.
One way is to find the 'grayscale' setting on your program and use that. You can check your values and then use the 'undo' action to go back to the original color. But what happens if the undo part doesn't work? All your colorwork is now gone. And you will probably want to check your colors more than once. You risk issues every time you try this.
But there is a trick that does the same thing using blending modes. And the nice thing is you can leave this trick in place so that you can turn it on and off whenever you want. It's easy to toggle back and forth between it.
First take your painting and create a new layer above everything. It doesn't matter how many layers you have, this will affect all of them. Don't clip the layer, just leave it at the top of your stack. In this example, I have a green ball on a layer, and a red ball on the layer above it. My new layer is on top of both.
Now get your paint bucket tool, select black and fill the top layer in entirely. It has to be total black for this to work. As you can see in the image below, the picture is now entirely black.
Now set the blending mode on that black layer to SATURATION. You'll see the balls reappear but they are once again back in grayscale. (Incidentally HUE and COLOR will basically do the same thing as SATURATION so if your art program doesn't have one of them, try the other.)
Now you have the ability to check your values again to see where you've gone wrong. In my case, you can see that my red ball is actually much darker than my green ball. The red I used has a much darker value. If I want those two balls to basically have the same value, I know I have to use a different shade of red to obtain that.
I can easily turn off this effect and go back to my colors by changing the visibility on the black layer. It can easily be clicked on and off any time I need to check the values.
I used this technique on my steampunk ladybug. I wanted to check if the red of the ladybug and the green of the plants had the correct values. The ladybug need to be slightly brighter to stand out against the background.