Trouble with Matte when exporting 2 layers (B&W overlapping)

Hello, my name is Jose.

We are working with Harmony 12 and we are having a trouble in our workflow when we export 2 layers separetly with alpha channel:

Our way to proceed is:

1 - We do a clean animation with a normal line.

2 - After this line is good, we create the Strokes (Create Color Art from Line Art)

3 - Once the Strokes are closed, we fill the Siluette with a black color Paint Tool. (example images just a circle)

4 - We have all the siluettes with black color. To export correctly, we export on PNG4 and, on Layer Properties we uncheck the option: Line Art Enabled. So the line doesn’t export, only the black fill till the Stroke.

5 - On the same layer we have all the strokes (we duplicate to have a back up copy), we “underline” where the light is going to appear (with a normal Line and then create the strokes, as before, or with the “Automatically create color art”).

6- Once we have the line that delimitate the light (and all the Strokes are closed), we paint with the Paint Tool on white. The Strokes of the edge of the siluette are exactly the same than the ones used for the light (because is the same layer). Also we uncheck the option Line Art Enabled.

At the end we have perfectly the two layers, but as you see on the example images, the mix of the two mattes (with that blur), becomes a thin grey line that we don’t want. We try to remove transparency (threshold:100) but the edge looks really pixelated when we export, and we need a perfect edge (it doesn’t work with any value of threshold. Is there any solution? or we have to go to postproduction to solve it.

Thanks in advance.


Hiya Jose, have you tired the Matte-Resize Node ? It’s a bit of a work around, but may work for you. I personally think there is some improvements TB can make to the way it exports Alpha, as it always seems to give a 1 pixel dark edge to alpha exports, it may have something to do with it not using Straight alpha, instead i think it uses premultiplied.

Something else that has worked in past for me, is to put it into Adobe After Effects and re-exported and that got rid of the 1 pixel dark line, a pain but worked…

Cheers, Jason

Harmony Premium and Storyboard Pro User


Hello Jason!! Thanks for your answer. It works perfectly, better than I though. I used to remove the edge in AE, but is not the ideal thing.

For the record, it works enough with a value of -0,24, more than that still will have the grey edge and less will cut the character matte too much.

Thanks again! Cheers!


One thing I am curious about is if you used a different file format to export. Instead of PNG4, I wonder if you would get the same edge artifact with TGA4 (Targa format)?

Hello Scungyho. Yes I tried lots of formats (TGA4 included) and I got the same problem. Matte Resize node works pretty well, you lost (a little bit) less edge that removing it on AE.

The reason why I was curious, is that in one of the manuals I read it said that all the formats that export with transparency (an alpha channel) were premultiplied but then I read where it said the PNG4 images were straight. So, I was confused, which was it, was PNG4 premultiplied or straight with the alpha? Or was that a typo? Anyway here is a screenshot of what I am talking about: