A true traditional in the most literal sense of the word would be a fixed blade of utility design. Small, large, in between, and in my studies of the folks that settled Texas (my home state) one or two knives of fixed variety were all the EARLY settlers had. Pretty traditional. The only variants we have in the Cowboy museum or the Texas Ranger museum or the Insitute of Texan Cultures are a few friction folders.
Read this forum and look at the pictures, and you can see that the definition here is a bit closer, one that seems to concentrate not back to Roman times folders, but to knives that became popular about 1850s or so (someone will correct that guess) and were made out of simple materials. Mostly, materials that were plentiful and reliable. So carbon steels, bone, wood, stag, celluloid, iron for bolsters, etc. are more accepted here.
Folders were folders for about a century, and while there were many patterns, there was little change in the actual design or mechanics of pocket knife. Blades, bolsters, liners, backsprings and scales all pinned together and you had a knife. Upscale knives were better fit, finished, and had nicer scale materials, but they were the same construction and same patterns for decades. Of course, there are exceptions to every rule as will be pointed out.
Traditionals changed to me when we started to see lockbacks in the 60s, and then LARGE folders. Too big to carry in your pocket, these were best carried in a belt sheath. Then came liner locks, screwed down pivots, screwed down scales, strange blade shapes, knives without bolsters, knives scaled with fiberglass (FRN), Micarta, Zytel, and on an on. Belt clips on handles arrived on the scene, super metals appeared for blades, and stainless steel finally grew up. Flippers, assisted openers, automatics, blades with holes in them to open the blade and thumbstuds became part of the landscape.
To my understanding, none of that works here. I personally think that is a good thing. The accepted model of the traditional here seems to be mostly folders that are of designs that harken back to the late 1800s to the 1960s, and are made in a similar fashion to those knives. They utilize the designs from that periods and most of the materials, too. Most of the knives from that time reflect the needs of tradesmen, workers of all sorts from specialized to generalized, and include designs for the casual user and gentleman.
As a few examples of accepted and not accepted: screwed together construction and ball bearings are a no go. Pinned together knives with bolsters and liners are great.
G10, Micarta, Titanium and Zytel are not traditional materials for scales, but wood, bone, celluloid, stag, etc. are so they are fine.
There are no flippers in traditional knives. Period. If the only infraction from a knife that fits all other requirements is that it is a liner lock, that is a mod prerogative to decide. Some pass, some don't. Lockbacks, again a mod judgement call, but it seems to be the only accepted models are the 40 - 50 year old Bucks, and those models only.
Stainless? Carbon? A topic too hot to touch. Both have a place in traditionals.
For me, I appreciate the craftsmanship of a well made traditional patterned knife. I think it takes a lot more skill to fit and finish the old patterns with the tools needed to do so than to take a pile of pieces and screw together a knife. Although I have a handful of those things, they are work knives and I have never really been attached to them. To me, they are what they are, a pile of assembled parts.
Ahhh.... but one can wax poetic about a fine traditional. Small enough to fit in a pocket, they can go places without notice. They become part of your daily kit, a reliable partner you rely on when you face the day. Instead of wearing down the G10 on a modern knife so that it looks ground down, a bone or stag handle smooth out nicely, wearing along with its owner. Bone and stag stain, turn colors on their own, and respond to how they are used and will turn out to be quite unique depending on the owner. A good patina on a carbon blade can take years to develop, but that blade has its own character, one it earned while in your hands. A stainless blade just seems to get scratched up and look ugly.
I look at my old traditionals and admire their wear and scars. I know they will go as long as I can. I look at a well worn modern work knife that I carry and I see worn fiberglass and scratched metal.
I know I am rambling on, but traditionals are just where it's at for me. I have no collector knives and all of my knives are used. And while I like my modern patterns, I love my traditionals.
Robert