Siqueiros was known for using pyroxalin instead of typical paint. (car paint) His portrayal of the working class wasn't complete without using the very tools found in their environment. He also created an illusion of space in all his murals. (such as the mural to the left). The ceilings seemed to continue much higher than they did.
Siqueiros is also credited to have created the largest mural project and installment in history. Which is now part of the Mexican World Trade Center. This building is known as the Polyforum. (some links below)