Just joined

[ronlamarsh]

Hello all, I just joined and am trying to get my feet wet with the Rawlins oil process. Needless to say I am experiencing a steep learning curve. My first question to the group is about potassium dichromate and what concentration is best. I am presently working with a 2 % solution but am having trouble with the inking. On my first pass the inking was good for the shadows very black but since I have not gotten anything but muddy grey. The first attempt I did thin the ink with jus barely half a drop of linseed oil, my later attempts were with straight lithographic ink. i am using the same negative for all attempts and have tried varying the exposure and soak times to no avail. So any thoughts?
Couldn't figure out how to post an image but I have one on the alt process area in the regular apug forum

 

[Jerevan]

Maybe upping the percentage of the dichromate, trying 3% as Derek Watkins uses in his book? If you thinned the ink at the first try and that worked out best, maybe the non-softened ink is too stiff for the 2% solution?

I am just thinking out loud here...

As for adding photos. it should just be a case of pressing the "add photo" link on the first group page.

 

[ronlamarsh]

Thanks I shall try the 3% solution

 

[ronlamarsh]

Just re-read "coming into focus" and John Barnier sensitizes his rawlins oils by immersing them in a tray with 3% potassium dichromate for 3 min: I have been using a hake brush and brushing it in until the gelatine surface is noticably 'slippery" as described in "keepers of the light" . Could the brush be part of my problem also?

 

[Jerevan]

I know that the surface is easily marked as the gelatin is so much softer. But I don't think the brush itself contributes to the problems with the muddy look - my guess is that it has to do with the relation between how soaked the gelatin is, and the stiffness of the ink. I'll read what literature I have, think a bit and get back to you on this.

Do you sensitize the gelatin papers in the way that John Barnier suggests?

 

[ronlamarsh]

No I have been using a brush

 

[Jerevan]

Been reading a bit. Abrading the surface can occur at two points: when sensitizing with a brush and when you ink it up. I have seen references to some people using Glyoxal for hardening the gelatin (immersion in a solution) a bit before doing the inking. The higher the percentage of the solution, the contrastier it gets, but also it gets hardened more as a result too. I have also seen references to using a Blanchard brush for the sensitizing stage.

 

[Jerevan]

Any progress, Ron?

 

[ronlamarsh]

Have been too busy at the "day-job" but am getting back to it soon. I havebeen experimaenting with using a coating rod for applying the gelatin wich gives a soother coating but it seems almost too thin. How do you coat your papers with gelatin?