Matte Finish - How?

I just got this year's New Zealand Silver Dollar, and I am very
pleased. It is the fifth and final one in the series, with each
having a distinctive look.

It's at http://stamps.nzpost.co.nz/Cultures/en-NZ/Coins/

It is hard to see on those pix, but it has a sort of dull matte
finish for the background. Contrasting to the bird and the
portrait being very smooth and shiny.

Which made me wonder... what did that require for the dies? I am
guessing that the smooth/shiny parts were polished. But, right
next to that, was some kind of surface treatment for the matte
background?

Perhaps there was some kind of chemical used to make a very fine
roughness on those areas of the die?

If anybody can refer me to an explanation, I would
appreciate it...


--
Get Credit Where Credit Is Due
http://www.cardreport.com/
Credit Tools, Reference, and Forum

"Coffee's For Closers" wrote in message
g...
I just got this year's New Zealand Silver Dollar, and I am very
pleased. It is the fifth and final one in the series, with each
having a distinctive look.

It's at http://stamps.nzpost.co.nz/Cultures/en-NZ/Coins/

It is hard to see on those pix, but it has a sort of dull matte
finish for the background. Contrasting to the bird and the
portrait being very smooth and shiny.

If anybody can refer me to an explanation, I would
appreciate it...

I don't have the reference handy (my Google is broken) but the Australian
mint achieves this effect by first preparing the dies in the usual way -
bright and shiny - then *very* carefully masking the bright areas and
sand-blasting the area which is to be frosted. I imagine the texture of the
"frosting" could be controlled by the grade of the sand/abrasive used.

The NZ coin you mentioned is prolly made by the Aussie mint - in that
fashion.

Google it anyway. I *could* be wrong!

--
Jeff R.

"Jeff R." wrote in message
u...

Google it anyway. I *could* be wrong!

Hehe.

They're called "Frunc".

Frosted Uncirculated.

http://www.ramint.gov.au/making_coins/frosted.cfm

(could be "Froof"?)

--
JR

On Thu, 12 Jun 2008 21:16:43 +1000, "Jeff R."
wrote:

"Coffee's For Closers" wrote in message
rg...
I just got this year's New Zealand Silver Dollar, and I am very
pleased. It is the fifth and final one in the series, with each
having a distinctive look.

It's at http://stamps.nzpost.co.nz/Cultures/en-NZ/Coins/

It is hard to see on those pix, but it has a sort of dull matte
finish for the background. Contrasting to the bird and the
portrait being very smooth and shiny.

If anybody can refer me to an explanation, I would
appreciate it...

I don't have the reference handy (my Google is broken) but the Australian
mint achieves this effect by first preparing the dies in the usual way -
bright and shiny - then *very* carefully masking the bright areas and
sand-blasting the area which is to be frosted. I imagine the texture of the
"frosting" could be controlled by the grade of the sand/abrasive used.

The NZ coin you mentioned is prolly made by the Aussie mint - in that
fashion.

Google it anyway. I *could* be wrong!

I have two Australian coins with the reverse look. A 2 oz. 2008 "Year
of the Rat" and also a 5 oz. series 2 Rat. They are both beautiful
coins (my two biggest silver coins) and I love the reverse-proof look.
Hard to believe they are not technically proof coins since they look
as nice if not better than some proof coins from the US Mint.

I missed out on the 2006 reverse-proof A.E., so I am glad the
Australian coins are available as an alternative, at least until 2011
when I am hoping the Mint will sell a similar set for the 25th
anniversary of the American Eagle.