The light colour heat transfer paper cannot be used on dark fabrics because the transfer paper is essentially transparent. An inkjet printer is not capable of printing white. As the result, anywhere that the image would have white, you will see straight through to the colour of the garment. When you print image on light color transfer paper, you should mirror the image before printing. Heat transfer paper can be used on 100% cotton garments, 100% polyester cloths or cotton and polyester blended fabrics.