the downforce and blade depth vary depending on each other. what is ones setting may be different for others. the condition of your blade also has to do with your settings. as the blade wears out, you may need more downforce.
True. Ideally blade depth and down force should be independent, especially with Graphtec's soft landing technology. But they're not independent. On my FC7000 I generally set the force to 20 and then diddle the blade depth to get that ideal crease but not cut indentation in the backing. This setting gets used for pretty much everything but laminated stuff where I set the force to 28 and drop the blade one more notch.
I've never quite figured out exactly what Graphtec's force settings represent. I talked about this at length to the head technical weenie at their factory and he admitted that he really didn't know either. It's not grams or some constant multiple of grams and, more confusing, it doesn't seem to be linear. Linear meaning that each unit of force represents a constant number. Like 20 is twice 10, which it's not. Figure that vanilla Oracal 651 should be cut with 80-90 grams of force. OK, then consider that the Graphtec's force setting maxes out at, what, 40? 60?Which is supposed to be 600 grams. If the force setting were linear then you'd set the force to about 5 or 6 to cut 651. If you do, you won't even scratch it. So figure 20=100 grams and 40 or 60 or whatever=600 grams. That means that the force setting is probably some sort of exponential or maybe geometrical curve. No one really knows, but it's damn sure not linear.