Re: Paper and platinum

Beakman (beakman@netcom.com)
Wed, 22 May 1996 06:08:41 -0700 (PDT)

>
> In-Reply-To: <199605211327.GAA21036@netcom20.netcom.com>
>
> David Fokos wrote:
>
> << I think that what it really
> comes down to is having a certain density of sensitizer on the paper.
> I've found that something on the order of 0.75 drops of sensitizer per sq.
> in. of coated area to be a good minimum target - >>
>
> This seems an awful lot to me - I have used less than this even with double
> coating. That is 15 drops for a 4x5 inch print.

Now that you all mention it, I probably *do* have a lighter density than
specified because when printing an 8x10, my coated area is actually
larger than 8x10. And, if any of you play Go you will know just how much
extra area 1/2" or 1" of border around the outside of the print area
adds. In fact, a 1" border all around (i.e. a coated area of 10x12,
rather than 8x10) will have 50% more area, so it is probable that I am
using something closer to 2 ml. or 2.5 ml. per 8x10.

I have also observed that I could possibly get by with a tiny bit less
sensitizer, however my formula works out to adding 1 drop of H202, and I
don't relish the idea of adding fractions of a drop -- and yes, I know I
can dilute it with water, but that adds extra water to the sensitizer, so
the formula is not *quite* the same... plus I prefer the convenience of
using the H202 straight from the bottle.

David