White lines surrounding selections

[scotwllm]

Whenever I create adjacent selections, I end up with a white line between them. I  understand it's due to anti-aliasing and pixels being at less than full tonal value to smooth the edges. Is there a standardized methodology for dealing with these partially filled pixels? 

[Bojan Živković]

Not sure what exactly you want to ask. There aren't partialy filled pixels. Pixel can have one color at time and only one color, cannot be partialy filled partialy transparent or filled with another color.

[c.pfaffenbichler]

Why did you knock out the black circle in the red area at all? 

If it is absolutely necessary you can either foregoe Anti-aliasing or employ »trapping«, essentially extending one area into the other one (in this case the lower one). 

[c.pfaffenbichler]

And just to make sure: Are you working with Selections and filling them on the same Layer or with separate Layers (with Layer Masks maybe)? 

Could you please post a screenshot taken at View > 100% with the pertinent Panels (Toolbar, Layers, Options Bar, …) visible? 

[melissapiccone]

What exactly are you trying to do that the anti-aliasing is interfering with? If you simply place the black circle in the red rectangle it would blend together. If there is a circle cutout in the rectangle and the black circle is slightly smaller you will see a slight gap as in your screenshot. Normal workflow is simply placing images overlapping one another, not matching up edges. 

[scotwllm]

Commercial printers use trapping to prevent gaps between colors. We don't send everything out to be printed, and the gaps can be just as glaring on screen as on paper, especially when enlarged. So I suppose what I'm looking for are generally accepted protocols for digitally trapping selections on layers. The end goal is to be able to turn on all the layers and the edges meet perfectly. I'm neither German nor an engineer, but that's the quality level I aspire to.

[c.pfaffenbichler]

Yolu can either abandon anti-aliasing and soft edges (which would seem like a bad decision) or stop knocking out the elements from each other. 

So let the lower Layer extend under the top Layer. (Not the whole area naturally, that would lead to other fringing, but at the »line« where the areas »touch«.)