Complex sentence: Sprague produced his wall panels by cutting them from fireclay blocks, heating and scraping them, and applying bold simplified motifs... pouring salted water... resulting in a warm toasted surface effect.
Split into simpler sentences: Sprague produced his wall panels by cutting them from fireclay blocks, heating and scraping them, and applying bold simplified motifs. These rugged clay surfaces were often finished simply by pouring a strong solution of salted water on to their surfaces... resulting in a warm toasted surface effect.