Bulino means "graver" in Italian. It refers to a specific technique of arranging lines and/or dots in a specific order for creating "photo-realism" on metal.
In America anyone that cuts, stipples, punches, fine lines or dots for shading scenes or scrolls... seem to think they are doing Bulino engraving. This simply, is incorrect. While I have seen beautiful engraving being done using other techniques it is not Bulino engraving, and the trained eye can see the difference between the two. I'm not saying one is better then the other. I'm just pointing out that there is a difference in the way it is done and the way it looks.
There are only a few people in the U.S. turning out top quality work using traditional Bulino techniques. Outside the U.S. there are quite a few engravers across Europe and England turning out top quality Bulino engraving. Choose wisely and look for a style that is attractive to you.
There are generally 2 traditional types of bulino scene work. One is done with dots and the other is done using lines. The method I use to do scene work is a mix of lines and dots that I have studied extensively, domestically and abroad. I use a microscope for almost all my work, but very comfortable working through a loop. When I traveled to Italy to study different engravers techniques, I was not learning engraving. I was learning how to create colors and textures in steel. Different shades of grays from very light to very black. In my opinion a combination of lines and dots is the best technique for accomplishing photo realism.
You have to try to make the thinnest, finest lines possible, parallel to each other and the spacing between determines how dark your area will be and if a darker effect is desired than a cross at 15 degrees will be necessary. A series of cross-hatches are cut and never at a 45 degree angle, always much less of an angle ( like 15 ). The finest technique is done with all curved lines and crossed with curved lines. Although this is quite difficult and careful planning must be made to avoid heel drag and other such problems. "Order" of cuts and "direction" is crucial. Layering parallel lines creates depth. Every layer of crosses lowers the area literally. If you cut a line with a 120 graver and cut a line next to it with the 80 degree, so it is the same width, the depth of the 80 will be much deeper than the 120 because it is so narrow. So in reality these cuts are not scratches on the surface they are very deep for their width. And that is where the darkness without paint comes in.
If you want an in depth study with the use of dots, pointillism drawing is the best subject to study. Very small dots concentrated in an area to create color. The closer together and more dense will create dark.
The further spread out and uniform the lighter the "gray" you will get. If you are dotting an object that is suppose to look round. You will want to dot the edges more densely and as you work to the center spreading them out. This will give the illusion of roundness. If you notice in the pic the darkest areas are dotted so densely that no shiny steel can show through. Also the lightest areas for example whiskers or gleams are not touched. All engraving was done around the perimeter leaving them white.