Buttons sprites size for Full HD and 4K Resolution

Hi, I am having a problem that seems simple but I couldn't find a good solution yet.

I have buttons sprites in a Sprite Atlas, each one has a 256x256 size. The problem is:

• In the original game Canvas Scaler, it is presented at 48x48 and 56x56 n some screens.

• When it reduces the 256x256 to 48x48 in the Full HD Resolution (1920x1080), it starts to have some visual artifacts as " Moiré patterns".

• So, to workaround I tried to reduces its size in the Import Settings to 128x128. But... By doing it, in the 4K Resolution it becomes very distorted.

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My first solution was to try Generating Mip Maps, so the 4K Res would use the max resolution of 256x256 and the Full HD would opt for a smaller one. Would you guys have another suggestion?

And about anisotropic filtering in the Mip maps options, is it a good one to try too?

Thanks in advance for any help.