Sorry- I guess I am looking for a synthetic that from a sonic point of view, performs as well as Ebony but that is solid black with very little sign of being wood, i.e. consistent color, little to no grain and certainly problem free in terms of warpage....
That being said, what is the best choice?
Well, you are asking for conflicting things. A synthetic product that is closest to ebony in mechanical properties, including its contribution to the sound, needs a structure similar to ebony. That is, cells, fibers, grain and similar resin content and density to ebony. That results in similar strength, damping, machining, gluing and wear properties, as well as the sound when installed on a bass. Rocklite was the best of that type that I've tried. It was very close to ebony in all the mechanical properties, and in visual appearance. It could almost fool you for ebony, except that it was too perfect. I called it Super Ebony, because that's what it was. It was an upgrade from ebony. And it was fairly expensive.
There are other synthetics of that type, which are trying to do the same thing. Taking a cell/grain structure of an existing wood and adding things to bring it up to the density, strength and properties of ebony. I've had some Royal Blackwood here in my shop. My buddy Jeremy used one on a fretless bass to try it out. Royal Blackwood is made by processing Purpleheart, roasting it and adding some resin and dye. Overall, I liked it. Its mechanical properties were close to ebony. But it doesn't quite look like ebony. The grain and the color aren't quite right. But I recommend it as a nice tough ebony-like fingerboard material. And it's not too expensive.
This Blackwood Tek that we were talking about above sounds interesting. It sounds like it's roughly similar to Rocklite in construction, using ground-up wood fiber and "natural" (non-petroleum) resins. From the pictures, it looks like it isn't pure black and has some streaks and visible grain. Which is okay by me, But you may not accept that. I'll be looking for Marko's report on the board he ordered.
We've covered several other synthetic ebony products in this thread of this same type. Some other wood that's been cooked and treated to make it closer to ebony. Our general opinion of them has been good, that they are tough black-ish fingerboard woods that work well functionally. But they look a little different from real ebony.
The other type of synthetic ebony alternatives are high-resin products, like Richlite, Ebanol, Rockwood, and a few others. These products are variations of Bakelite, which is a stack of sheets of paper, thoroughly soaked in resin and cooked and pressed into sheets. These products all have a high content of plastic resin, with some wood-product reinforcement inside. They are effectively sheets of plastic, and their mechanical properties are different from wood. They don't look, feel or sound like any kind of wood.
Richlite is made from layers of paper, about like Bakelite. A fingerboard blank is pure black, no streaks, no grain, nothing. It looks and feels like a sheet of black plastic. Not as shiny or brittle as Acrylic (like Plexiglas), but close. It machines and glues like a sheet of plastic. When you tap on it, it sounds like......plastic. As a blank sheet, it's pure black on the surface, but when you machine down into it (like radiusing the fingerboard surface), you see some wiggly grey-ish streaks, that don't look like wood. Some people like Richlite for guitar and bass fingerboards, but I don't personally. It's not wood.
That's the conflict: Do you want it to look, feel and sound like ebony? Or be pure black with no grain or streaks?