>Hi Bas,
>
>Well now I have got you exactly where I want you
are you shure? I'm still in Amsterdam
>Here's my problem: I seek to recreate the depth of tone of the wet gum
>print permanently in the dry print
>
>That is either an extra thick gum arabic or a gum arabic with sugar and
>glycerine added (which if it proves successful I will reveal in detail for a
>mere $395). My questions, therefore, are:
>
>1. Can you (or other paper wizard) suggest a "varnish" to shine up
>the print like water? Or,
>
>2. Warn me of dangers lurking in the idea. Would the gum arabic mix, for
>instance, flake off in time? (I tried hardening it by mixing with
>dichromate and exposing to light, but that took the shine away.)
Since I am a little short of time some thoughts right out of my head:
1. in olden days watercolours (especially flower still lifes) were
hightened with gum or gum/egg-white/sugar mixtures in all kinds of
combinations. This was done to give, in real life shiny, parts of flowers,
leaves, insects a more "dramatic" effect. So we are talking here of partial
applied "gloss". The layers applied are very thin (diluted with water)
since the difference in gloss with the surrounding watercolour and paper is
easily reached in this way. In my oppinion this is the exact reason that
this kind of gloss survived: the layers are very thin, porous to water and
work with the paper instead of against it. Conclusion: what we want is a
thin layer with more or less the same properties as the paper it is applied
to.
2. the varnish (to give it a name) should not yellow, or at least within
acceptable limits and that also in accordance with the
yellowing/deteriorating of the substrate it is applied to.
3. the refractive index of the varnish should be almost the same or the
same as the refraction index of the substrate (gum) so as to not to give a
haze as you describe. (so why not use gum?)
4. the shine or gloss of a layer is also dependant of the smoothness of the
layer, very smooth layers tend to be more shiny (polishing metals &c.)
Most varnishes accomplish this by shrinking upon drying, the solvent
evaporates and the remaining solids "huddle" up in a smaller space and bond
to form a layer*. Matting agents often are powders that disturb the surface
so the reflection of light on the surface will be disturbed in a very
regular way.
* the problem here is that in this way tension is introduced between the
layers that eventually will end in flaking or cracking. On strong stable
substrates as wood, concrete floors and what have you, this shrinking is
not regarded as a problem because the substrate resists the pull of the
varnish, paper is not capable of resisting this pull and will deform. When
a varnish is used that in itself is dimensionally stable it will flake, or
crack off the - dimensionally unstable- paper (see 1 above)(albumen prints
have this problem).
5. when I was young my father tought me printing in the darkroom, he used a
heated mirror press to make glossy prints, (in dutch the thing is called a
"glanspers" none of my dictionaries could help me out as to give the proper
name in English). Maybe some tests with applying gum and drying it in a
controlled way could help you further. As explained above the thickness of
the layer is directly coupled to the flaking/cracking of it so the highest
gloss with the thinnest layer should be found.
hope this helps, I will try to find some more information
on this subject.
PS the Paris meeting was very good and pleasant, beautifull prints and lots
of fun. You will get a short report later: Klaus Pollmeier, Terry King and
me agreed to make one off-list to spare you multiple messages. BTW next
year we could do something similar in my workshop in Amsterdam (no time
limit, tables, refreshments and excursions - what can we think of more?) so
hold on.
Jonge Eland papierrestauratie
eland@knoware.nl
t +31 20 623 79 89
f +31 20 627 32 23
VeRes (Dutch Association of Professional Restorers)
postbus 11503
1001 GM Amsterdam
PAPER IS ART IS PAPER IS ART IS PAPER IS ART IS PAPER IS ART IS PAPER