[tenaja]

Does anybody know what it costs to texture a machined aluminum mold? Obviously, there are huge variations depending on the mold, but say, for a simple 2" x 2" x 1" box with .25" radii in the corners... is it closer to $100, or $1,000? Who does it?

[Torque1st]

Your injection molder can get it done or your mold maker. It is probably over $100 but not real expensive. It does blur details and can mess up parting lines.

[DJPLAST]

Mold texturing an aluminum cavity can be done. Make sure that the vertical walls have enough draft to facilitate part removal.
Here is an address of a company that has been around along time, they do good work. http://www.mold-tech.com/index5.shtml

If you are looking to get a matte finish, a mild glass bead blast will do the job, but be sure to have enough draft (2 degs per side) on vertical walls. Leave some stock on the parting line and remove after blasting. If the parting line is already finished, mask the parting line with duct tape, minimum of
2 layers.