Avoiding Brush buildup / Overlap

[rgbrobot]

Hello everyone. I'm using photoshop on an assignment to do what the prof is calling "Sketch-over rendering" We've loaded a sketch in, and are using the brush tool to paint in color, shadows, and highlights.

There's a number of other posts on this topic, but I feel they do not apply to this situation. Here's why.

My goal: To paint all my shadows on one layer, with varying opacity.

Problem: In my painting process, I may not have a steady hand (painting with mouse), and may miss a spot, or paint an area that needs unpainting, thus erasing. Through this process, there are small spaces that need the shadow touched up. As long as I have a steady hand, I can cover the area perfectly in one stroke. If I have to go back and touch up, any overlapping strokes build up, rather than retaining the same opacity. This behavior makes perfect sense in some areas, but not specifically for my application. (I've tried to show this in my example, painting a second line to get closer to an edge, or a cluser of clicks to fill in a tight area.)

Proposed solution found on web: Many people on various forums have all proposed the same solution: "Just draw with 100% opacity, then lower the layer opacity."

Why this doesn't work: Because I am varying the opacity of my brush around the painting to achieve lighter or darker shadows, my painting requires variable opacity, not painting with 100% opacity

Side note: this also happens when trying to paint in a straight line from A to B. Click to establish first point, shift, click the second point, and there's a small circle of darker material at the first click. This is demonstrated in my example at 100% hardness, where it's most visible.

Note: I found the build up option in the brush settings. It was unchecked and locked. No matter the state of either check or lock, it still builds up. (Perhaps it's the wrong word to use.)

Here's my brush settings. Screenshot attached. In normal mode, opacity at 100 after a separate task. Opacity is listed in my original screenshot. I did see the airbrush build up effects was on. Turned that off and it makes no difference.

[Omar.Fathy]

It is the nature of brushes, you are drawing using opacity. If you don't like this overlap, you can use opaque colors.
Use obaque colors in different layer and you can change the opacity of the layer itself.

The build up option in the settings is clear when using graphic tablets even if you didn't release your pen. It apply the effect when you draw back on the previous line.

[Adham34074188m4hf]

Simply use smudge tool or blending brush to blend various areas together.

[Chris 486]

Hello!

What you are experiencing is intended how the brushes digitally interact. Maybe one of these options may help?

Paint your shadow larger then your intended area and do all clean up with your eraser tool.

Make multiple layers and set each one to the opacity you need. Keep your brush at 100% and switch between the layers. You can then merge them together at the end to have one layer

You can try using the pen tool to create the shapes you need to shade with different opacity as well.

[D Fosse]

The others are right. Painting at 100% and lowering the layer opacity is the way to do it.

The way to do what you specifically want here, as Chris says, is to split it into several low opacity layers. Then merge them afterwards. I do that a lot.