I recall when the gentleman was experimenting and developing these. From his early efforts, it looked to me like he starts with a shallow pool of clear resin and then drips spots of dye onto it in various patterns which might - or might not - look like the real thing (meaning, either the real thing they used to cut from actual tortoise shell, or the real thing as made by whoever supplied Fender's early celluloid PGs - take your pick). Depending on the consistency of the unhardened clear plastic, the exact colors of the dyes, and the drip pattern, there is a wide variety in the final product. Obviously there's a considerable amount of time and manual effort put into each one; they're not just printed like dollar bills or punched out like coins. Tortoise has an obvious visual depth to it which isn't remotely duplicated by conventional printing processes. (I'm assuming here that the current manufacturing process is basically the same as that developed in the early days, before Spitfire was a business operation.)
Tortoise shell was originally of commercial value because of its mechanical properties - a unique blend of affordability/cost, stiffness, toughness, workability, machinability, and other things materials geeks get excited about - rather than looks, but all we notice nowadays are the visuals. The appearance of generic modern tort is so ghastly that, by comparison, the Spitfire version is great. But to my eye it still doesn't look like tortoise, of either the real or vintage instrument varieties. So to me, the price is excessive. But if one must have something resembling tort, the Spitfire product has a huge lead on the competition.
