I didn't realize that he was so old.

After the original Star Wars came out, I bought the "Art of Star Wars" (edited by Carol Titelman) which had a lot of his artwork in it.

I loved his "angular" style.  It made things look more technical and in some cases menancing.  In addition to sketches, he did tonnes of production paintings.  After Revenge of the Jedi, I bought a reproduction series of his paintings and had them posted on my walls.

He was very talented and prolific.