The OP presumes in the examples cited of "process" that process means that particular line of craft that results in the artifact. In Quinn's post, we begin to see a somewhat enlarged definition, but the expansion of the idea remains incomplete as we return to the example of "process" as being the wet plate. I was waiting. I thought it was going to develop into something larger, but thanks, Quinn, you helped me formulate some thoughts that this thread has been stimulating.
The underlying assumption seems to be that the work is directed toward production (that is, a product) and that the "process" is what gets you to that product. We do this, we get a "thing". We do that, we get a different "thing". In a world that is dominated by the material, I suppose that this is not to be avoided.
I'd like to propose another element to add to the mix. Process is not necessarily limited, as an idea, to a particular mode of production, such as platinum, wet plate, albumen, etc. Process can also mean the whole arc of the work, which includes the definition of the scope, the concept, the field in which it is done, the particular mode in which the artifact will be produced, the public intended to see it, the venue where they will, etc.
Let's take an example from another medium. We could inquire among the painters about how they define "process". The ones I know would find this an interesting question, I'm sure. Let's presume that we have two painters, both of whom use the natural world as the source of their subject matter. Both use paint, and we can presume that they use the same medium, let's say oil. One is an abstractionist, the other a realist. Is their "process" simply the medium they are using, oil paint on canvas? Or is the "process" much more inclusive? Wouldn't it include the way they gather the information, one through drawing in a sketchbook, the other taking a photograph? Wouldn't it include the way in which they generate their concept and think about what they are doing, applying that thought to divergent materials, both physical and conceptual? Would it include a loose charcoal drawing on the canvas to define basic structure vs. the projection of a slide on the canvas? Wouldn't the "process" be peculiar to the way each artist works and include virtually all elements that go into the conception, selection of subject matter, choice of materials, methods of production, and, perhaps even more important, how one would use what was learned in the production of one artifact in the process that may result in the next? In other words, perhaps, process might be the way one moves through what one does, not just how one produces the artifact materially. In either case, though, the artifact does result.
Lots of questions. This issue is at the very root of my own work. I recall a remark by Jack Welpott, many years ago, where he defined a basic difference between a process orientation and a product orientation. In those days (1960's) there was very little so called "alternative process" work going on, so that did not enter into it. He was referring to the way an artist works. "Taking pictures" vs. "making photographs". I very much took that distinction to heart.
There are lots of clichés out there that refer to this, but remember, clichés come from something that starts out as true and fresh, then get stale. You know, the journey vs. the destination -- (we're supposed to think the journey is the important part, but when we go on vacation we get on an airplane and the journey is no fun! So, we reveal that we may, in fact, be hypocritical.). But in the studio, unless we are mass producing for a public that only wants one thing (ugh) presumably we are practicing a process, regardless of the medium in which we work.