Once your image is ready to be printed you may need to reverse the orientation of the image, depending on the transfer paper being used. If you are using a heat transfer paper for light colors, then you will need to reverse or mirror your image's orientation so that your image prints out backward onto the paper. This is especially critical if you have text in your design. The text should be backward on screen or on the printout. Ideally, the program or printing options will have an opportunity for you to reverse the image.
Since most opaque papers are pressed face-side up, there is usually no need to print the image backward, but it’s always important to read the included directions for the specifics of what needs to be done. It's also a good idea to print a preview copy of your image onto regular copy paper before actually printing it on the transfer paper. This will help you verify that the image will print in the correct orientation, doesn't fall into your no-print zone (when using registration marks) and is sized appropriately, as the on-screen view can be deceiving. Also, remember that the colors you see on your screen will not always be exactly what print out.
As with any desktop publishing project, consider the color of the item you are pressing onto when selecting colors for your designs. This is where you may need to decide to use an opaque transfer paper rather than a regular heat transfer paper. It’s a good idea to test your design on “scratch fabric” before
applying it to your final t-shirt or another garment. Some fabrics may require more heat and pressure than others and may not show off your design as well as you expected. Therefore, it is best to determine the best specifications for pressing before you press your final product.