Answer the following question: Given the following passage "The indirect method of applying tesserae is often used for very large projects, projects with repetitive elements or for areas needing site specific shapes. Tiles are applied face-down to a backing paper using an adhesive, and later transferred onto walls, floors or craft projects. This method is most useful for extremely large projects as it gives the maker time to rework areas, allows the cementing of the tiles to the backing panel to be carried out quickly in one operation and helps ensure that the front surfaces of the mosaic tiles and mosaic pieces are flat and in the same plane on the front, even when using tiles and pieces of differing thicknesses. Mosaic murals, benches and tabletops are some of the items usually made using the indirect method, as it results in a smoother and more even surface.", answer the following question. Note that the answer is present within the text. Question: How some the indirect method unify tiles?
Answer:
helps ensure that the front surfaces of the mosaic tiles and mosaic pieces are flat