Keeping texture quality when Quality Settings change

Is there a way to make certain textures not decrease their resolution when you select a Quality setting that has "Texture Quality" at "Half Res" (or lower), besides disabling mip maps completely for the texture?
To explain why I want this: I have a few certain textures that need to be high-quality when you're close to them so that they are readable (they include text), but I'd still like them to have mip maps so they look good from far away, and keep the ability to lower the rest of the texture qualities as part of the overall Quality.