What are professional quality knives made from

Mostly steel.

The old-school carbon steel isn't as popular today as it was fifty years ago. However, modern alloys, metallurgical improvements, and manufacturing advances have made stainless steel knives understandably popular.

That said, I'm convinced that a seventy-year-old butcher using a carbon steel knife can do a job as good as a twenty-year-old butcher using whatever newfangled stainless knife can do.

Plus, I'm sure most of the world's home cooks don't have super fancy knives.

But if you have tons of disposable income, sure, splurge on the best. At least you will enjoy the pride of ownership of a well-crafted tool.

The generation I grew up in, stainless steel was pretty much a no no in the kitchen; knives were high carbon steel. They sharpened and kept an edge very well, but needed to be kept dry, and cleaned immediately if you cut something acidic. After not thinking about knives for probably thirty years, I decided a while back to try some different styles and was amazed that stores seemed to have nothing but stainless steel. I finally, trepidantly, bought a stainless steel santoku, and was amazed to find that modern, high carbon stainless takes an excellent edge, and keeps it well. As to what's popular in restaurant kitchens, don't know or really care.

Steel. Carbon steel is popular. The type of steel preferred will change according to the cook and according to the job at hand. A professional chef might spend hours chopping at hard vegetables like carrots and squash, so they want something with heft rather than a thinner knife more suitable for slicing fish. Although people will often say that all you need is a good Chef's knife, a paring knife and a bread knife, many like myself will have different knives for different jobs in the kitchen. And because they're pretty. One of my japanese knives could easily chip when breaking down a set of ribs, so I'll use a cheaper heavier knife. They're both steel but one is more brittle than the other.