When did the Mint start "sandblasting" Proof coin devices and do non cameo coins exist after that?

lsica

When did the Mint start "sandblasting" Proof coin devices (or whatever they do to cause a constant and conistent field and device contrast) and do non cameo coins exist after that?

gumby1234

They use a laser to frost the dies now. I'm not sure when it started. Probably a slim chance of having a non cameo modern proof

gumby1234

From Coin World April 2013

Just a small excerpt from the article

The technology is initially being used on the Proof 2013-W 5-Star Generals gold $5 half eagle and the Proof 2013-P 5-Star Generals silver dollar.

The Proof 2013-S 5-Star Generals copper-nickel clad half dollar is being struck using the standard Proof finish, according to U.S. Mint officials.

Laser-frosting technology is also being used in the production of the Enhanced Uncirculated 2013-W American Eagle silver dollar, which will be included in the two-coin West Point Mint 75th Anniversary set slated to go on sale May 9.

FlyingAl

Sandblasting was in use from the early 1900s, if not earlier.

Chrome plating extended die life in the 1970s (roughly) and modern day laser frosting made it even better. Today's proofs are all DCAM.

Sapyx

It's my understanding that regular-cameo proof dies were traditionally made by sandblasting the entire die, then polishing away the frosting on the high points on the die (which are the fields on the eventual coin).

Reverse-cameo dies were harder to make via sandblasting, because they first need to cover up the un-frosted parts of the die with tape or resin or something before hitting the entire die with with the sandblaster. Using a laser is much easier, in this regard.