physautotype my first go

Hello to All,
Since some of my sugestions have been tried by participants in this Thread, with very negative results, it has occured to me that some might think that I am "full of It". So, here is a set of B&W in-camera color separations that I was Able to scan against a black background.
Here is what I did: Heat treated 10 grams of rosin,
Disolved it in 500 ml of denatured alcohol,
Added 500 ml of Water,
Dip coated 4 clean 5x7 glass panels (both sides)
Dried verticaly overnight,
Exposed via sunlight for 3 houers,
Developed over Sunnyside Odorless Paint Thinner,
10 minutes,
Let dry.
Scaned each with a flatbead scanner against a black background.
Regards,
Bill
UH-OHH! My images do not have a URL They are just files in My Documents. Anyone know how I can get them here?

wildbillbugman said:

Hi Bruce,
Given "optimal" conditions for each, is there much difference between an image made with lavender oil and rosin?
Bill

Click to expand...

Bill they appear to be very simular

wildbillbugman said:

Hello to All,
Since some of my sugestions have been tried by participants in this Thread, with very negative results, it has occured to me that some might think that I am "full of It". So, here is a set of B&W in-camera color separations that I was Able to scan against a black background.
Here is what I did: Heat treated 10 grams of rosin,
Disolved it in 500 ml of denatured alcohol,
Added 500 ml of Water,
Dip coated 4 clean 5x7 glass panels (both sides)
Dried verticaly overnight,
Exposed via sunlight for 3 houers,
Developed over Sunnyside Odorless Paint Thinner,
10 minutes,
Let dry.
Scaned each with a flatbead scanner against a black background.
Regards,
Bill

Click to expand...

Now thats an idea Dip coating, both sides ? did one side stay frosty ?I see you have used a 50/50 mix, good pics, how do they look just held up to the light ?

Hi bruce,
Somehow my response to your last post did not get "published".
Glass plates develop cleanly on both sides. I turn over the glass after 5 minutes, midway through my standardized 10 minute development time. But, honestly, I think that development is complete in less than the first 5 minutes. I like Oderless Paint Thinner becausae it is nearly impossible to over-develop.
Held up to the light the plates have a clear background (black in the illustrations, The image is a pearlesent, off- white.,
Regards,
Bill

thanks bill

Looking at the results here maybe this rosin process needs long exposure times to harden the mix, given it only takes a minute or so to develop in kero fumes, might try a 3 hour exposure, as i have only been useing 1.25 hours as i was worried about over exposure.

Any more progress heather ?

brucej said:

thanks bill

Looking at the results here maybe this rosin process needs long exposure times to harden the mix, given it only takes a minute or so to develop in kero fumes, might try a 3 hour exposure, as i have only been useing 1.25 hours as i was worried about over exposure.

Any more progress heather ?

Click to expand...

Since I am not currently involved in attempting physautotype, I hadn't posted, but I think you are on the right track. I have experimented with the heliograph process, and found that it exposes from the top of the emulsion down, meaning if when my exposure was insufficient, the image would begin to show as I developed, but would then wash away as development continued. This isn't the same process, but I feel perhaps the same effect applies.

Bruce,
I think that this process is not unlike many of the old processes that require negatives with considerably higher contrast than do silver gelatin prints. Since it is a positive process one
needs a lot of density in the "shadow" areas to alow for enough exposure of the highlight areas and not over expose the shadow areas. I find "paper positives" as opposed to film or transparency possitives to be very suited to this process. For negative processes I almost always use Pyro or Pyro-Cat development of film.
For experemental purposes I use Ink Jet Velum as regular plain paper is too dense for Physautotypes.
Regards,
Bill