How can I stop or disable anti-aliasing / feathering in Photoshop?


I've never really found a solution to an issue that's been plaguing me since I first experienced it in Photoshop CS, and now, five versions later, it's still bugging me!

What is it? Well, seemingly randomly, Photoshop decides that when I use the solid fill bucket, or the pencil tool to "paint" something within a marquee selection, it will either "feather" whatever I'm doing to the pixels outside of the marquee, or "anti-alias" the inside border pixels of the marquee.

Sometimes, I actually want this to occur, but it doesn't regardless of what I do (and I end up using the eraser tool with a low opacity to recreate it) and then sometimes, when I really don't want it to occur, it does.

Here's an example screenshot of what I'm talking about: alt text

See how it's randomly added pixels outside of the select? (The selection was drawn with the poly marquee tool, with feather set to "0" - the green colour was added with the pencil tool, with normal mode and opacity set to 100, and size set to 70px).

This MUST be a setting somewhere that I've totally missed, and it's driving me barmey!

Please could you advise me on how to disable anti-aliasing in Photoshop?

5/26/2014 2:44:00 PM

Accepted Answer

Firsly feathering and anti-aliasing have different meanings, though for small a feathering radius the results are similar. "Feathering" effectively means fading the selection boundary out slowly, and is slightly different to "anti-aliasing" which means using intermediate values to smooth out jagged edges.

You need to turn anti-aliasing off in addition to setting the feather to zero to get what you want, which is a sharp rigid boundary. There should be a checkbox in the tool palette, next to the feather radius box:

alt text

(screen shot is from a very old version of Photoshop!)

It's worth noting the black and white "marching ants" selection border only ever shows the 50% threshold of the selection, and is therefor just a guide. If you save the selection to an alpha channel you can see the selection opacities of every pixel, and thus see your actual selection.

10/20/2010 1:39:00 PM