You are running into two different problems. By default, most UV texture layouts are based on a 1 to 1 aspect ratio. So, if you make a square texture map and apply it to a rectangular surface (such as a wall 1 unit high by 2 units long) your texture will get stretched in one direction. Solution is to make the texture map the same aspect ratio as the surface to which it is being applied. The other problem is one of resolution (you mentioned dropping pixel lines). Even if the aspect ratio matches, if the scale that the texture appears in the final render is significantly different from the original map, the texture will be stretched or shrunk & antialiased accordingly. No way around that other than to make the map somewhat close to the same resolution that it will appear in your final render. That is to say that if your map is 1000x1000, but in the final render it only covers 200x200 pixels, naturally you are going to lose some detail as you would in any rescaling process. One size does not work as well for all renders. In this case a smaller map would yield a more faithful reproduction of the original than would a larger, higher resolution map.