RE: "speckling" v "staining "

Judy,

>
>From the very first tests I did with glyoxal, I found it hardened better
than formaldehyde
>

How did you determine that glyoxal hardened better than formaldehyde?

>
1. A student noticed that her sized paper yellowed during storage. I'd
never seen that previously. It develops now, however, that rinsing the
the paper after a 5-minute hardening bath prevents most or all yellowing.
>

I do this and get no yellowing with glyoxal.

>
2. I've found that glyoxal working solution doesn't keep -- even for a
day (no traces of odor remaining). How long are folks keeping it?
>

I toss mine after use.

> 1. excess heat during sizing

I'm sure I don't have excess heat.

> 2. drying emulsion by heat

I don't dry the emulsion by heat.

> 3. unsuitable paper

I think Rives BFK is a suitable paper.

> 4. off brand paint or difficult color (eg carbon black)

I'm using M. Graham.

> 5. scrubbing during application of emulsion

No scrubbing just a gentle brushing with a hake brush.

> 6. heat and/or humidity while emulsion is drying

Nope.

> 7. long wait before development

Nope.

> 8. overly aged emulsion

Nope.

> plus, of course some wacked out-gelatin for the size.

Fresh made Knox.

> 1. another variable may be the water in other localities which changes the

whole equation
>

Distilled water but not from New York City.

> 2. perhaps some folks aren't using the glyoxal one-shot?

I've already answered that one.

> 3. newer papers I haven't used have other variables that give trouble.

Just Rives BFK.

> 4. another thought about speckles -- I do NOT NOT NOT mix paint with gum
and keep in a jar for later use. IME the paint settles at the bottom and
is very difficult to remix smoothly.
>

I've discovered a way to ensure that the pigment and gum are mixed
thoroughly every time. I use a dremel tool with a cone shaped brush
attachment to blend the mix to a homogeneous creamy puree prior to coating.

>
Maybe it's not well remixed and thus
speckles -- or anyway, IME an accident waiting to happen. Putting in a dab
of paint from the tube is so easy, and much easier to adjust color &
ratios, why complicate things?
>

The coating is smooth an bubble free.

>then squeegee excess gelatin (illustrated P-F #9), hang to dry,
and bathe the dry paper separately in the glyoxal.
>

Yep I've done that. I squeegee the excess gelating bathe in glyoxal
separately.

Tomorrow evening I'm going to size with glut on Fabriano Extra White and
Rives BFK. Later next week whe time allows I will repeat the process with
glyoxal and the same two papers and we will see what gives.

I've noticed that except for you, Katherine, Chris, Kate, Dave, Clay, Roman,
and Keith no other gum printers are commenting. I was hoping that we would
hear from some other gummists. Perhaps everyone has tired of the discussion,
I know I have at times.

Don Bryant
Received on Sat Sep 10 21:46:36 2005