With most engineered flooring prefinished in the factory, a very high standard of finish is achievable. In many products the coating to the exposed upper surface consists of a multi-stage system including fillers, sealers and final coats with additives such as aluminium oxide to provide a tough wear resistant surface. Coloured stains may also be used in the coating system to add different colours or tones to the boards. The coating is done in a controlled environment with UV curing that provides a fully cured finish at the end of the process. Products are available in different gloss levels from a satin or low sheen finish to a full gloss level. It should however be noted that not all suppliers may provide both in the range of products they sell.
From some suppliers product available unfinished so that it can be sanded and coated on site. Sanding and coating on site can be beneficial in permitting the final appearance to be achieved at the end of the project when floor installation is required beforehand. It also provides for coating choice. Although a high standard of finish is achievable, site sanded and finished floors generally contain some imperfections and where such imperfections have a limited effect on the appearance of the floor, the imperfections are considered acceptable. Provided below is a photo of an engineered floor that was sanded back to bare timber and coated. The appearance is quite acceptable even though at an oblique angle in reflected light the surface is not as smooth as the original pre-finished boards. This is shown in the inset.