American Architectural Foundation
The American Architectural Foundation (AAF) was founded in 1943 and is headquartered in Washington, D.C. The AAF is a non-profit educational organization dedicated to cultivating the public’s understanding of architecture and the human experience. The AAF initiates education and outreach efforts, which foster public participation in the design process, encourage public stewardship of America’s architectural heritage, and promotes alliances between architects and the communities in which they live and practice. Each year AAF is on the ground in more than 75 cities across the country, helping local leaders use design as a catalyst for innovation and action.
So far I really like this, much better than Das clay. It has no unpleasant odor and is very smooth, takes detail well. Has a distinct leather hard phase where you can work that way, really neat. Hasn't been long enough to really test finished strength though as that takes two weeks (it's dry though in a day or two).
This is not only the best eraser I've ever used, it's the ONLY eraser I'll ever use, despite the best sales pitches in art shops to get me to change. Cleans superbly, soft to use, no discoloration on the paper and cheap as chips...I don't believe it has a competitor