The report notes that existing methods of anodizing or painting aluminum surfaces produce different colors, but mostly all of them are glossy. It is much more difficult to create a black aluminum surface since in most cases only a dark gray shade will be obtained. The company believes that this color cannot be considered truly black, so the developers have created a new technology.

The company believes that simply applying dye particles to the pores of the anodized layer is not enough to give the surface a true black color. Part of the problem is that the surface is glossy, which allows it to reflect a lot of light. If you make a layer that can absorb light, then this approach will help you achieve true black. Apple suggests using a metal pickling process to form the light-absorbing layer. The light that is not absorbed by this layer is diffusely reflected from the surface. As a result, it becomes less shiny and more matte.

One of the patented options is to create a matte black surface by electrochemical anodizing of aluminum or aluminum alloy. Another option makes it possible to achieve this effect during the deposition of the coloring elements on the metal oxide layers. In this case, the metal substrate can be made of any suitable material, including aluminum, titanium, or steel.

Despite the fact that the patent application dates back to 2019, Apple has not applied this technology in practice before. However, it is possible that in the future the company will release a matte black MacBook or some other device, the body of which will be painted in real black.