Whether you're an ID student working wood or an architecture student making foamcore models, you need a pencil to mark dimensions on the material prior to cutting it. And you quickly learn that on high-tolerance projects, a regular and unsharpened pencil can have you off by as much as 1/16th, or worse if you're a sloppy cutter; the things need to be kept sharp.
So next you figure mechanical pencils are the way to go for accuracy. But mechanical pencil leads always seem to break off when they're jostling around in your ArtBin or toolbox, and those little plastic tubes that hold the replacement leads like to disappear when you're pulling an all-nighter. Plus a mechanical pencil lead has the same problem as conventional pencils—they're worthless for marking on black foamcore or darker woods like walnut.
One potential solution is the Accutrax Pencil Blade, a piece of graphite shaped like a utility knife blade.
It drops a razor-sharp line right against the ruler, never needs sharpening and can be retracted inside the handle, like a regular blade, to keep it safe during transit.
Different colors, most importantly white, solve the dark material problem.
However, I say "potential" solution and can't anoint this thing a "win" for a couple reasons: They clock in at $5.50 for just three blades, not exactly art student prices (and even worse, some retailers are selling the three-packs for as much as $12); and I can't find anyone who actually sells the colored versions of the blades. I think the concept is sound, but that the price will have to come down to disposable levels in order for these to take off.