Silkscreen come in a wide range of colors including both black and white. As a PCB maker, it is necessary that you supply additional Gerbers for every screen layers. You also need to describe the order in which the printing should be done. You should also keep in mind that the registration is perfectly done and is not overlapping. Dealing with black silkscreen should be done just the same way you carry out other printing processes.
If you are designing the black silkscreen by yourself, it is important that you check misalignment of silk layers. This ensures that the background does not show through the knocked areas. You also need to create a color separation to eliminate problems of having more than one color overlapping. Printing the resultant images on board is easy. However, you will encounter problems especially if you will be dealing with inks that resist common solvent.
The other important thing that you need to consider is the board that you will use. Notice that no standard board is specified for use. So it may be necessary that you talk to board houses and give them the specification of the board that will serve your needs. If you want to use different colors somewhere, you may need to paint it yourself.
Note that the process seems complicated, but it is doable. Alternatively, if you do not want to do it yourself, it may be necessary that you find someone who is willing to do the job for you. The black silkscreen can be prepared by using one color and adding a solder mask layer. You may also utilize different patterns in the screen layer. In conclusion, you have an option of choosing solder mask, silk, or bare laminate instead of metal. It allows you to add the patterns you may be interested in quickly.