Heat transfer paper has become a popular garment decorating method for many hobby and commercial businesses and a lot of people who are getting into doing transfers may notice that papers generally fall into two categories: for light fabrics and for dark fabrics. It is important to understand the difference between the papers as well as which color shirts are actually considered light and dark, especially when it comes to the different color shades and tone.
Light fabrics include: white, light grey, heather grey, and pale color shades.
Dark fabrics include: brighter and saturated colors, dark grey, black
There is a grey area of some colored fabrics that can be considered either category by some, such as bright neon colors or certain pastels which allow for a very dark or black design to be transferred well by using paper for light fabrics.
So what is the real difference between these papers? Papers for light fabrics are very thin and the white of the paper tends to transfer as an almost transparent layer that blends nicely into the shirt. Since the transfer is so thin, it partially relies on the white of the fabric to make the design look more opaque. If the fabric is a darker color, for example a bright red, the design in general will be tainted red because of the base color of the shirt. For that reason, papers for dark fabrics were made thicker and much more opaque in order to avoid the fabric color showing through. These papers transfer the white of the paper as an opaque sheet, which is why the design has to be trimmed down or any white leftover will transfer solid white and will not blend in with the shirt. Dark fabric papers tend to have a feel similar to a sticker or vinyl onto the shirt vs. papers for light fabrics that feel more like a screen print and takes on the texture of the fabric.
Another difference, most seen in papers for inkjet printers, is the way the paper is applied onto the shirt. Papers for lights are pressed face down on the garment and then the backing is peeled off immediately after pressing (hot peel). It is a less time consuming process since you can trim close to the design but it doesn’t have to be exact to the edge. Papers for darks are trimmed or cut with a vinyl cutter so any excess background can be removed, and then the design is peeled off the backing and placed face up on the shirt, then pressed with a protective sheet on top such as silicone or Teflon. Once the pressing time elapses, the design has to be in most cases cooled off before removing the protective sheet of your choice (cold peel).
As the photos show, Jet Pro SofStretch transfers are almost transparent and take on the color of the fabric which is why papers for light fabrics generally do not work on darker or colored fabrics. Additionally, because Jet Pro paper is so thin, you can see a loss of vibrancy as the paper can only take a certain amount of ink saturation which is compensated by the softness of the transfer. 3G Jet Opaque and other papers for dark fabrics however are completely opaque and the white of the design comes entirely from the white of the paper with no see through. For that reason, the colors also pop more but the feel of the transfer is much thicker and feels similar to a thin sticker on top of the fabric. Most people with white or very light garments prefer the screen printed feel over the thicker feel, but papers for dark fabrics are definitely compatible with all colors.