Sentence:  But it is also true that Braque was the consistent pioneer in the use of simulated textures as well as of typography ; and moreover , he had already begun to broaden and simplify the <WSD>facet-planes</WSD> of Analytical Cubism as far back as the end of 1910 . 
Meaning of the word marked with <WSD> tags:  the plane of a facet of an object (as of a cube)