2D Toolkit preprocesses sprites and text mesh data to a target size to reduce the amount of work required at runtime. These parameters tell the system what the target viewing resolution and camera are. Target Ortho Size refers to the ortho size of the camera viewing the sprite Target Height refers to the height of the target resolution In most cases, all you will need to do is set up these parameters correctly, and every sprite you create will be Pixel Perfect by default. Sometimes, you may have more than one camera in your scene with different parameters. In this case, enter the details of the camera which will view the sprite, and every created sprite will be pixel perfect.