Digital BW, The Print

Nick,

The varnish I used is "Liquitex Gloss Varnish", which is a water based 
acrylic for flexible surfaces.  I had some left from my experiments 
last year so I tried it again using your procedure (15% dist. water 
added for dilution, two thin coats).  The dilution seemed to take care 
of the bubbles (after drying) but when applying it was still very foamy 
- almost like rolling on soap suds.  The print was on H Photo Rag (300 
gsm) and after treatment and drying the paper texture was accentuated 
and not smooth at all.  It looks almost like a very coarse pearl or 
pebbled finish paper when viewed at an angle to the light source and 
the reflections are somewhat distracting.  Perhaps some addition of 
matte medium to reduce the sheen would help.  A pad applicator or brush 
as Antonis suggested might also reduce the foaming problem.  I've tried 
the rod application procedure before with hydrocote and although this 
does give a very smooth finish I found it very difficult to get 
consistent results.

Carl

On Tuesday, August 10, 2004, at 01:29  PM, Nghi H. Nguyen wrote:

> Hi Carl,
>
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Carl Schofield
> <scho@m...> wrote:
>> Do you have any problems with bubbles and foaming when applying the
>> diluted Liquitex Gloss Medium and Varnish coating with the foam
>> brayer? I tried using a closed cell foam paint roller with the
>> Liquitex Gloss Varnish (not the one with medium) last year and had
>> problems with bubbles forming in the coating when rolling.
>
> Before answering your question I'd like to say that I probably forgot
> to mention in my last posting that my technique does not work with dye
> ink because the water-based acrylic medium probably will dissolve it.
>
> Now the problem with foam. What type of gloss varnish is that you're
> using? Is it water based or solvent based? In my earlier test when I
> used the gloss medium full strength I found as I ran the brayer over
> and over again all the bubbles disappeared. Work the liquid into the
> brayer then roll it hard on the tray to squeeze out excess liquid.
>
> After you run the brayer over the print surface a few times you'd find
> the foam disappears. The nice thing about the 10-15% diluted
> water-based liquitex is that even if you can spot tiny bubbles on the
> surface they will all disappear once the print dries. This is due to
> the shrinking nature of the polymer. It works like the swellable
> polymer on some inkjet papers, only that this polymer once dried is
> much tougher and is water proof.
>
> You might have not only used your varnish full strength, but probably
> too much of it, too. Please retest using your current varnish and try
> to reduce the amount, I believe if you dilute yours a little and
> spread if really thin you'd find the bubbles will be gone. Experiment
> with running the brayer over the print many times.
>
> But if your varnish is solvent based ... I don't think it will work
> with your inkjet matte paper because the solvent will seep like crazy
> into the substrate and make it translucent.
>
> For certain special prints which I keep for myself I coat with a layer
> of Dorland Wax Medium to provide additional protection.
>
> --nick
>