How to create a sharp custom brush from picture?

[MichaelK]

I used a white PNG, 12 x 6 px to create a custom brush, but I don't get a clear / sharp brush, but a blurry one instead.

Also the ratio changes by changing the brush size. Where is my fault?

 

AP 1.5.1 Mac

[- S -]

I'm not sure whether your attached pic is showing the brush on a canvas at 100% view, or a small canvas blown up to greater than 100% view.  However, 12 X 6 px is pretty small, therefore if you increase the brush size it will need to guess the extra pixels hence the blurry brush.  So, when you create a PNG for a brush nozzle, make it much bigger (Affinity Photo brushes go up to 4096px X 4096px).

 

 

I don't know why the ratio is changing when you change the brush size, as I haven't seen that before.  Maybe make sure all the settings in the 'Dynamics' tab are set to 'None' in case what you're seeing is actually jitter.

[gdenby]

I don't have AP, but am supposing that the brush engine in AD is the same. I suspect that part of what is happening is that the brush stroke is being anti-aliased. For instance, if you zoom in on a 1 pixel line, you will see that it is several pixels wide. And on 1 pass, all the pixels will be somewhat washed out, as they are being blurred into the background. So far I haven't noticed that the anti-aliasing can be shut off.

[Alfred]

If you want sharp edges and no texture, why create a brush at all? Why not simply use the Pixel Tool? :unsure: