Welcome to TVPaint Community forums !

I hope this is the right place to post this.
I have been playing with the layer blending functions and found something that I can't get to work. Maybe it's human error (mine) or not understanding the function properly. Otherwise I guess this could be a request for improvement.
I forgot how to attach more than one image so I will do a bunch of replies.

For this test I drew a simple shape:

On the layer above I drew some lines in black and light blue. For fun I set the layer opacity at 57%. This is what I see when I toggle this layer on.

To learn how to use blending I'm looking at:
http://www.tvpaint.com/doc/tvp11/index. ... troduction" onclick="window.open(this.href);return false;

Following the instruction I drop the top layer on the on below and get this popup menu:

If used while merging layers the result of the blending function "Darken Only" is just as expected. Success! This is similar to what I would experience if I would draw some lines over the shape with the brush set to "Darken Only".

Now I want to get the same effect but without merging layers.
Here I looked again at the documentation: "The solution is to mix the layers but without needing to modify them. To do that, the layers should be mixed "on the fly". There is a popup menu in each layer in the left side of the layers panel which allows you to select the way to mix the layer, it is called the Blending Mode."

I really like this idea!!

But when I try it by setting the top layer to "Darken Only" the result looks different. It looks as if it assumes the area where I didn't draw anything (which looks white) is the color white and the lines are visible over white. Only the light blue lines over the green shape vanish.
I would like to have an option where I can define which layers the blending affects in this case layer "Untitled 2". With the idea that I get the same result I got when I blended while merging.

If I try "Lighten Only" on the top layer. The result seems to be as expected and one might think it's successful.

But adding a black layer underneath reveals that it functions like "darken Only":

It actually looks almost the same as when I draw the light blue lines on the top layer without the layer set to blending. Like here:

So currently the blending functionality "on the fly" does not seem useful for how I thought I would like to use it.
To double-check I try "Lighten Only" while merging layers. The step that makes this work seems to be the clarity of dropping one layer on to another.

So again while merging I get the expected result. This blending while merging is a very nice functionality that I appreciate.
But I really like "on the fly" (the way you described it in the documentation) as a concept because it would preserve the original art (helpful for later adjustments) while merging alters the original art. My suggestion would be to give us an option to imitate the way we can specify a certain layer (or layers) when merging so that blending also works "on the fly" in a way that gets a result that looks the same as what we get when we blend while merging.

Greetings to the team in Metz. I appreciate your work!