2 drops for 7x17 or 12x20 (4ml and 6ml solution respectively)
1 drop for 8x10, with total drops #1 and #3 and NA2 at 18+18+NA2
You could dilute the tween, or pipette for less than one drop (I typically pipette) if you are using 4x5 or 5x7.
I tried this paper for the first time today and did tests on both sides. I got really salty blacks and lower than average sharpness. I used one heavy coat and I didn't use tween. Is this the expected result?
What process were you testing? Kallitype? Cyano? (probably not - no blacks) Gum? Platinum? VDB? Carbon? .............
sorry, forgot to include that info.
I'm doing pt/pd with cold bath developer. I did a single coat for a 5x7 image using a puddle pusher. I used 7a 1b 6pd 3pt (this amount of coating was more than enough for the area). I dried the image with a hair dryer and then re-humidified for 90 seconds, flipping the paper every 30 seconds.
Another problem I noticed was that the coating was slightly sticking to the negative. There was a sound as I peeled them apart and a little residue left of the negative. This drying/humidifying procedure is identical to how I was working with the platinotype with no issues related to sticking.
Okay, I pulled a decent print today. Precoating in distilled water as bostick indicated didn't improve the image much but by soaking the paper for 30 seconds in oxalic acid and then drying the sheet until it was slightly damp I made an acceptable print. After that I humidified for 15 seconds on each side and I developed the print in potassium oxalate at 110 degrees.
It looks much better than before. the image is clear and no longer dominated by the white specs. However the image still shows a consistent scattering of small white specs after it hits the developer. Also, I am coating the side bostick and sullivan indicate and there is a distracting dimple pattern in the paper that is particularly visible in light grays. I will post a scan tomorrow when it is dry.
Anyone else worked with this paper to do pd/pt? It would appear that it is buffered since the acid bath improved the print so drastically?