Layer Mask Not Fully Applied (Affinity Designer 1.9.1)

[simon bd]

Hi,

Using black on a mask should block the layer image completely—but it doesn’t.

1. Attached Image 1 shows a two-layer drawing, one layer for the character and one for the dark background. The dark brushstrokes of the background intentionally overlap the character.
2. A Mask is added to the background layer in order to hide the part where the brushstrokes overlap the character (Image 2). 100% black paint is used.
3. Image 3 shows the result: the brushstrokes almost disappeared, but not quite: there remains a faint ghost of the background on the character (about 5% grey). You don’t notice it right away, but it would show at printing (dangerous!).
4. I resolved the issue by working destructively. I loaded the mask as a selection and deleted the overlapping brushstrokes. This removed the 5% grey completely (Image 4). Now if a mask can’t fully hide the image, how is it possible that a selection, loaded from the same mask, fully deletes it? There is something wrong with the mask.

Thanks,

Simon

 

[Sean P]

Hi simon bd,

Would it be possible to attach the document files that your sample images are created from please? It will make things easier to investigate what might be going on.

However judging by the second image that shows the mask, the black used is not RGB0,0,0 but is actually RGB22,21,21. This sounds to me as though your document is possibly using CMYK? There is a known issue that using 100% K does not fully erase a mask. 

[simon bd]

Hi Sean,

Unfortunately, I deleted the masks after applying them; but please tell if you’d like to see the file anyway.

Yes, it is a CMYK document. But the screenshot is RGB, which might explain the black not being 0,0,0. And yes, I’m using grayscale 0 as black, which should be OK on a grayscale mask.

I wanted to report the problem; glad to hear it’s a known issue, I’m sure it will get fixed.

Thanks for the quick answer,

Simon

[Sean P]

1 hour ago, simon bd said:

Hi Sean,

Unfortunately, I deleted the masks after applying them; but please tell if you’d like to see the file anyway.

Yes, it is a CMYK document. But the screenshot is RGB, which might explain the black not being 0,0,0. And yes, I’m using grayscale 0 as black, which should be OK on a grayscale mask.

I wanted to report the problem; glad to hear it’s a known issue, I’m sure it will get fixed.

Thanks for the quick answer,

Simon

It definitely should be ok, I agree, I'll get it updated with development. In the meantime if you set your brush to CMYK 100,100,100,100 you should be able to fully erase

[simon bd]

Thanks for the tip, Sean!