ruby lith????

[laran]

What is ruby lith? I need to find a source and don't even know what it
is (using as my red filter for my enlarger - possibly)

thanks

Laran

[Peter]

http://en.wikipedia.org/wiki/Rubylith

[David Nebenzahl]

On 10/8/2009 2:36 PM laran spake thus:

> What is ruby lith? I need to find a source and don't even know what it
> is (using as my red filter for my enlarger - possibly)

Rubylith (one word) was (and still is, if it's still available) a trade
name for transparent red masking film used in the graphic arts (notably
in the making up of flats for offset printing, known as "stripping") as
a photo-opaque film (orthochromatic photosensitive materials like offset
printing plates are insensitive to red light). Cut-out areas in printing
flat could be covered with Rubylith to eliminate printing marks on the
plate caused by light exposure.

From the Madison Avenue-ese "ruby" (meaning "red") + "lith" (as in
offset lithography).

--
Found--the gene that causes belief in genetic determinism

[David Nebenzahl]

On 10/8/2009 3:54 PM David Nebenzahl spake thus:

> On 10/8/2009 2:36 PM laran spake thus:
>
>> What is ruby lith? I need to find a source and don't even know what it
>> is (using as my red filter for my enlarger - possibly)
>
> Rubylith (one word) was (and still is, if it's still available) a trade

> name for transparent red masking film used in the graphic arts [...]

Yep, it's still available: f'rinstance,

http://www.hyatts.com/sign/ulano-rubylith-universal-15x50yd-T36645

(a little pricey at this site--$213 for a 50 yard roll. Might want to
shop around a little ...)

[Bob AZ]

Laran

I used to use it from time to time for Safelight filters. Used to get
it from an art supply shop. They had it in 20X30 or about that. I
still have some but have not used any in years. Do a google search.
Maybe Amazon.com has it.

Bob AZ