[alt-photo] further cyanotype observations

[Christina Anderson]

Dear All,

I have posted a visual at the URL below which shows the different paper "speeds" with traditional cyanotype. I have tried to be as consistent as possible with humidity, room temp, rest time before exposure, drop count, development time. All exposures are 15 minutes--my usual "baseline printing time" for cyanotype to arrive at my "standard printing time" for that paper. With Fabriano AEW I usually up that BPT to 20 minutes.

 At any rate, it might be a helpful visual for you on how different papers have different speeds with cyanotype, as well as different graininess. Traditional 1:1, Edwards UVBL light box. You will note why I was so surprised at Buxton's speed: maximum black comes at step 8 on a 31 step tablet, whereas on other papers it may come at step 3--a difference of 1 2/3 stops. That would result, once b+f of step wedge and pictorico is taken into account, in a difference of 4 versus 11 minutes.

The little arrows on the visual, if the web shows it, should point to the first line of demarcation visible between steps, so above the line is the first max black.

Masa, Buxton, Platine, and Cranes Cover are the clear winners in the grain category IMHO. Platine is just an all around great paper for a lot of processes. I also can't believe how thick and sturdy Cranes is once wet. It thickens quite nicely but remains very smooth. The others that grain I would be more careful with the brush choice and amount of solution next time (more).

Some of the papers are cream colored base, some are white. A couple bled (masa and BFK175gsm I think). The BFK is not the normal BFK, btw.

Still have another batch of papers to test, but you get the picture...nothing so exciting as Charles' nice gum prints to see, just some boring step wedges, but anyway.

One last thing: I mixed up my own homemade (not store-bought) Ware's formula and it, in fact, clears nicely, so the b---ch clearing problem was most likely due to old/contaminated chemistry in the purchased product. 

Doug, will be interested to see what you think are the differences, if any, between Cot320 and Platine :)

Chris

http://christinaanderson.visualserver.com/Text_page.cfm?pID=1953




Christina Z. Anderson
christinaZanderson.com