Rules Clarification: Costume vs. Professional armor

A clarification to what counts as Costume versus Professional armor has been made.  The relevant text has been clarified to read as follows:

In Knight Realms, the value of a piece of armor is judged by two things: the amount of protection it gives (what it covers and how sturdy it is), and how authentic it is. Good, thick armor that looks like it was cobbled together in your garage will do, but a suit of armor that is made from authentic materials and design will offer greater protection.

This eliminates the discrepancy that armor that "looks real" but is not gets Pro grade status.

I take it that this means that aluminum is not to be considered professional grade?

Correct.  We'd thought about this one for a while, but any deciding factor other than confirmed facts (i.e. - materials, instead of how good it looks) left the door open to arguments over how realistic a physrep is each time a new one is evaluated, and too many gray areas when assigning AP.

Out of curiousity, how far does this extend?  Steel arguably dates back to 4000 BC for extreme examples, with very obvious widespread steelmaking past 1100 AD, but clearly modern steelmaking techniques were not in use at the time.  Is any sort of steel allowable, or are there certain limitations, such as density/weight?  I doubt that there'd be much objection to, say, stainless steel being used for practicality concerns, but something like titanium alloy might be pushing it.

I might be missing something.

Metal armor made from a lighter material is costume grade now?

Latex armor that looks like plate, but isn't, is definitely Costume grade, no matter how cool it looks.  "Shark Mail" (the micro-weave chain mail used by bodyguards and in fisher's gloves) that is machine made from modern materials is also past that line, as nothing that fine could ever be made by hand.  Other materials, I'll try to get a clarification on where the line is.

The root of this update is that there was a discrepancy in the rules.  One spot stated that it MUST be completely authentic, the other spot implied it only had to LOOK authentic.  When we realized this, we had to choose one or the other.