Sorry Lnfortun, didn't actually see your post until now.
Here is an explanation of the hard surface Papers:
CL Hard Surface I is for smooth hard surfaces. You print mirror image. Place substrate on press with printable side face up. Then place printed transfer with printed image face down. Once pressed, peel off transfer paper and only toner will be left.
In the case of crystal, it will vary. If doing a glass mug, it is basically the same application method as sublimation but with different temperatures and higher pressure.
If doing a glass or Crystal plaque with Hard Surface I, it could be on the front or the back of the substrate. If on the front it will have to be mirror imaged. If on the back, it will be printed right reading. Again hard surface on Crystal will create a transparency effect. Most awards shops like to image on the back of the crystal to make the image more durable.
As for the Crystal, there is no backing to peel off (absolutely no peeling is required). Basically you are heat pressing the entire transfer paper to the crystal then trimming the excess paper on the edges off. The printable side is also the adhesive side. And you are printing only on to the back of the crystal. Any areas on the crystal where there is no toner will be white. Once pressed you will trim any excess transfer paper off the edges of the crystal.
Hope this helps.