Re: Opaque v Transparent Pigments

Hi Alex,
I wrote a note about this the other day but it seems to have got
lost, so here's another.

My goal in giving so much information about pigments on the list has
always been to help people make informed choices about pigments, to
understand the characteristics of pigments and using that
understanding, to choose pigments that will help them achieve their
artistic goals. It sounds like you're doing that beautifully, and I
enjoyed your comments.

But I might make one small comment about what you said about having
to watch when using transparent pigments to make sure the black
doesn't creep up the scale (in other words that the shadows don't get
blocked) when you're working with CMYK. In my experience, any
blocking of the shadows is a result of using your pigments too dark,
especially cyan but also sometimes magenta, if you're using a deep
magenta. While I think the idea of printing with a lighter opaque
color to lighten the shadows is an ingenious way to deal with the
problem, and while I think it might make a really interesting color
print to do it that way, I would also say that you will get good open
shadows rich with color if you use transparent pigments in a lighter
pigment mix. You can get a deep black by overlaying the three colors;
there's no need to use them so dark that the overall print is too
dark and the shadows are blocked.
Katharine

On Jan 10, 2006, at 1:59 PM, Alex Chater wrote:

> Hi
>
> From my experiences gained from Temperapint, I would just like to
> share some
> of what I have come to understand regarding opaque v transparent.
>
> With transparent colours I have found that each coat darkens the print
> overall. The print is going toward the black, coat by coat as each
> subtracts
> more light, its a one way road where I have to keep an eye on what
> the black
> is doing lest it creep up the tonal scale. I find that transparent
> colours
> are only a real problem when I tried to do all the work with just
> CMYK. I
> feel that these printers need transparent colours to work well. For
> me they
> do the bright chromatic colours well but don't work so well for shadow
> colour
>
> Opaque don't seem to work like this. It allows some ability to
> lighten an
> image so that if a shadow falls dead you can bring some colour and
> definition back because of the opacity. I also find that the range
> of the
> colour is wider because many opaque pigments if rolled out thin are
> effected, to a greater or lesser extent, by the colour below. If I
> chose a
> suitable opaque colour to put on, then the colour below can work
> really well
> producing a rich result that CMYK would be unlikely to give me. This
> resultant colour can then be further moderated by a later
> transparent layer
> on top
>
> I feel that it's horses for courses. I like to use each for what
> they are
> good at. Transparent for bright and lively colours and opaque for
> subtle and
> rich colours. Together for me they give a rich and wide diversity
> of colour
>
>
> Alex
>
>
>
> ----------
>
>> From: Hellena Cleary <hellena@hncleary.plus.com>
>> To: alt-photo-process-l@sask.usask.ca
>> Subject: Re: Opaque v Transparent Pigments
>> Date: Mon, Jan 9, 2006, 5:13 PM
>>
>>
>
>
>> I would like to add my own bit of information on the use of
>> transparent
>> pigments, as I use them in the Tempraprint process. As
>> Temperaprint is a
>> multi-coated process, for me it is vitally important to use
>> transparent or
>> at the very least translucent colours in order to be able to
>> predict how the
>> colours will merge with each other in the final image. An opaque
>> colour
>> simply sits on top and can prevent the other colours from coming
>> through and
>> blending properly to produce the final desired colour. I use acrylic
>> colours to mix with the dichromate and the transparency,
>> translucency or
>> opacity is written on the container. My preferred choice is Liquitex.
>> Hellena
>> ----- Original Message -----
>> From: "Katharine Thayer" <kthayer@pacifier.com>
>> To: "alt photo" <alt-photo-process-l@sask.usask.ca>
>> Sent: Sunday, January 08, 2006 7:07 PM
>> Subject: Opaque v Transparent Pigments
>>
>>
>>
>>> Hi Folks,
>>> It occurred to me that I didn't really have to wait until I have
>>> time
>>> to reprint these prints wiith a better color balance, to demonstrate
>>> the difference between opaque vs transparent pigments, since opacity
>>> vs transparency is after all a different issue from color balance or
>>> tonality. So I've simply enlarged a part of each of the prints, to
>>> show the difference I was trying to describe, that I could see in
>>> the
>>> prints but that I wasn't sure translated to the electronic
>>> reproductions.
>>>
>>> I've always said that in my own experience, to my own eye,
>>> transparent pigments shine through each other in a way that forms
>>> clearer, brighter color blends than opaque colors can possibly make,
>>> and that's why I prefer transparent pigments, especially for
>>> tricolor prints but also anytime I want to use different colors and
>>> have them form clear color blends. I think these enlarged details
>>> show those qualities quite well, and maybe I'll just use this for
>>> the page on pigment opacity and transparency, without spending any
>>> more time on it.
>>>
>>> These test prints that the enlarged details come from are the same
>>> ones I showed the other day; the same separations were used for
>>> both
>>> prints, and both prints were most probably printed on the same
>>> sheet
>>> of sized Arches bright white, as I was cutting larger sized sheets
>>> into small pieces for these small test prints, and these two prints
>>> were done consecutively.
>>>
>>> http://www.pacifier.com/~kthayer/html/optrans.html
>>>
>>> Katharine
>>>
>>>
>>
>
Received on Sat Jan 14 15:16:24 2006