Unfortunately, I haven't discovered any gimmicks, contraptions, or magical potions so far (unless spending hundreds of hours stabbing paper with a tiny graphite spear counts.) But I have learned a few things that make these cast drawings different from most other places I've seen.
GCA Cast Drawing:
**This is by no means an authoritative guide to cast drawing, just my own observations and interpretations of what I've picked up so far!
Graphite instead of charcoal.
No particular brand of pencils (I'm currently using blue ones... but sometimes they're teal or green!) My friend Katie used a 4H (THE SAME PENCIL) for her entire final cast (!!!) Some people use HB/2H. I use 4B through 6H because I am a nerd and I like to hold 12 pencils at once.
It's not that no one cares about backgrounds... it's just irrelevant for the purpose of these drawings: to create a sculpture on paper. Other cast work I've done has been about the way lights falls on an object in an environment. It almost seems like the same thing, but GCA cast drawings are about exploring the object in its purest form, rather than the way light is bouncing in the space and on the object in front of you and hitting your eye, which brings me to--
When light hits the cast and bounces into your eye, it's taking quite a trip. It has to deal with things like smudgy windows, stains and dirt spots on the cast, and trying to get to your eye without being messed up the the light that's trying to get in your eyes from all the other lamps/lights/windows around the room. Then there's "simultaneous contrast" which means a little shadow in the light area looks extra dark because it's surrounded by light, while the white cast against a super dark background will look extra white. If you put a white piece of paper behind it, you'll usually see that it actually gets a bit darker at the edge, but compared to the inky background, it's hard to see the subtleties. ALL THAT to say... just "drawing what you see" can be tricky business. The approach GCA takes, is to picture how "light-facing" any given surface on the cast is, imagine the same "light-facingness" on a sphere, and make it the corresponding value.
I like to think of this as the "moon" concept. The shadow areas that are defined during the block-in are filled in with an extremely smooth and even darkish tone (chosen by the artist.) No smudging devices are used!! Straight-up pencil work. I call it the "moon" concept because it's like how you don't see any light in the shadow on the moon. With one primary light source used to conceptualize the form, the shadow areas that are not receiving direct light can be extremely simple without sacrificing the 3D quality of the drawing.
While the shadows are flat, the light areas (anything being hit by the primary light source) have no outlines and no areas of "flat" tone. It's as though you're a tiny spiderman crawling across the cast--you're always moving towards the light or away from the light. "Edges" are just points where we can no longer see the form. Occasionally you go slightly insane and think think you're actually creating something that is hovering off the page.
SO! All of that will be better explained as I progress in my new cast, but it's a decent Cliff's Note's version of the main differences I've noticed between my previous cast experience, and the process at GCA.
Laocoon... My New Best Friend