Gum over Pt/Pd with PiezoDN


#1

If anyone is using (and / or teaches or knows of a practitioner) PiezoDN with the gum over Pt / Pd process please let me know as I have some questions. I am only interested in single or duotone application over Pt / Pd (not full RGB / CYM color prints).

thanks!
Michael


#2

Hi Michael, yes i am printing gum over Pt using PiezoDN, what is your question? I will try and help, cheers Stuart


#3

Hi Stuart,

My questions pertain to single color, duotone and / or tritone prints (not full color rgb / cym).

  1. For a single color gum over do you use the same negative for the gum over layer or a separate negative that was printed using a master ink curve file specifically made for the gum over layer (obviously the same image)? If you are using one negative (i.e. one master ink curve) for both the base Pt / Pd image as well as the single color gum over, do you use the same exposure time for the gum layer (or does it very based upon the gum over color)?

  2. In a duo-tone (with a shadow and a highlight negative) or tritone (with three negatives: shadows, mid-tones, and highlights) gum over did you linearize and therefore create three different master ink curves? Or did you print these negatives using the master ink curve you used to print the base Pt / Pd image?

  3. Have you ever used Platinum Revere paper for your gum over prints? And if so any feedback, issues, etc. you could share?

Thanks Stuart!

regards.
Michael


#4

Hi Michael

  1. I use a gum specific negative. Created by identifying max ‘black’ exposure, then using this to identify the ink limit to augment the master curve and then 2 or 3 linearisations. It’s not a perfect fit but is much better than anything I have been able to get with EPSON ABW and PS curves. I chose a Magenta pigment to establish the curve, and yes there will be differences between pigments but that is something i will ‘try’ and control by varying the dichromate/gum ratio, exposure and development . Exposure time is 1/3 of the Pt/ Pd exposure time.

  2. I have yet to make a gum duotone with PiezoDN. I have only been using PiezoDN for the last 2 months. Previously when using Epson ABW I did make separate negatives for the different tones, highlight/ darks or warm/ cool etc. but used the same PS curves . I do plan to make PiezoDN duotones and will use the same technique, ie separate negatives for the tones but using the same curve.

  3. No sorry, I use COT320 for all most all my Alt printing and size with PVA 1:1 with water after Pt/Pd/ Cyanotype before the gum layers. Sizing can make or break a full colour gum print but when using as a gum over its not so critical as you are usually only adding gum to add colour to specific tones.

trust this helps,
Cheers, Stuart


#5

Stuart,

Very helpful! Thank you!

A couple of followup questions:

In regards to #1 (above), do you use your master curve for your Pt/Pd print at the starting curve for the gum layer (and then as indicated 2 or 3 linearisations)?

Some practitioners have “complained” that PVA gives a “plasticky” feel to their print (I know it is very paper dependent). Have you experimented with PVA at 1:2 or 1:3?

Do you have a website where I can view your work?

regards.
Michael


#6

Hi Michael,

  1. No I use the the original master curve for each process after augmenting with the ink limit. I use the Malde Ware process for my Pt/Pd so started from scratch for this curve as well.

I originally used gelatin to size but this adds an extra day and is pain and since coming across PVA have used it ever since. I have tried lower dilutions but sometimes end up with staining problems.

Keep in mind registration of successive print layers. If detail is important or i know I’m going to be going for 2 or more gum layers I will dry mount the paper to Al sheet with fusion 4000 using an iron before Pt/Pd. You can also try pre-shrink before Pt/Pd as well.

Yes i have a website, see www.labrettophotography.com
cheers


#7

Thanks again Stuart.

Thanks for the link.

Beautiful images; wish I could see the prints in person!

M.