Are your textures being resized? PlayCanvas automatically resizes texture to be a power of two (POT). So an image that is 100x60 will be resize to be 128x60.
You can disable this temporarily in the scene settings under “Asset Tasks” -> “Texture POT”
By default, imported images will be resized to the next highest power of two. For example, an image that is 400x400 will be resized to 512x512 on import. This is done because the graphics engine cannot utilize mipmapping with non-power of two textures. However, this behavior can be overridden by disabling the ‘Textures POT’ setting in the Asset Tasks panel before importing a non-power of two texture.