Because soda ash from Egypt was no longer a viable input due to cost and inefficient trade routes, glassmakers in Northern Europe began to utilize wood ash, typically from beech or oak trees, to make glass by 800. Wood ash was later combined with sands to concoct hard, heavy, opaque glasses desirable for cutting and engraving. An important note is that the output glass were not delicate pieces of art desired by a worldwide market as Venetian glass would be centuries later. This glass from wood ash was typically used for practical items, like windows. The photo of a European Beech tree was obtained from Wikipedia. The image is licensed under Creative Commons to share if attributed to Jean-Pol Grandmont.