Struggling to get consistent prints with New Cyanotype chemistry

[jrhilton]

I think you would be better off skipping the New Cyanotype chemistry and go back to the basic stuff. Not to throw shade on Mike Weir, but we aren't chemists like him. I've always thought the New Cyanotype process was overly complicated chemically and has too many issues if you stray from perfect, but you already have found that out. Besides, a lot has changed since he came up with that process. I don't think you need it at all anymore to produce beautiful cyanotypes. Maybe back in the 90s, but now you can use the standard chemistry and get fantastic results, and it is much more simple that way. Occam's razor for the win.

I agree with what Patrick says, namely stick with the original process. I never had great success with the new one, but can get great looking prints using the original process. Finding the right paper is key though. I think I have mentioned this in the past on here but the best paper I ever tried (in terms of detail and image quality) was Epson heavyweight matt paper, but struggled to clear unexposed sensitizer - 13 years later the test prints still look great.

I also add a drop of Tween 20 to the mix, and find it helps get a nice even coat.

 

[Patrick Robert James]

I'm guessing you mean Mike Ware.
Not the Canadian Mike Weir, of Green Jacket fame:
View attachment 304914

Well if he won the Masters then I guess he is still a chemist, only of a different type! Lol.

 

[jonmon6691]

I'm super grateful for all the feedback from everyone, and despite the ups and downs the challenge itself makes this all worthwhile to me.

With regard to adding tween 20, I've seen this come up a few times but no one is specific about how much and in what concentration (perhaps its not critical but I also don't know that either). One drop to the whole 100mL of sensitizer? or a drop to each small batch of sensitizer as I apply it to paper?

On the subject of acidity, I think I'm gonna order a pack of litmus paper strips so I can keep track of that variable. I watched a video from North Light Photography about balancing tween's alkalinity with an acid, seems like thats a theme

 

[jnamia]

I agree with what Patrick says, namely stick with the original process. I never had great success with the new one, but can get great looking prints using the original process. Finding the right paper is key though. I think I have mentioned this in the past on here but the best paper I ever tried (in terms of detail and image quality) was Epson heavyweight matt paper, but struggled to clear unexposed sensitizer - 13 years later the test prints still look great.

I also add a drop of Tween 20 to the mix, and find it helps get a nice even coat.

I haven't used tween, but I agree 100% with what you and Patrick said. The original process is so simple it should be illegal.

 

[nmp]

Regarding Tween 20: Strictly using surface science, one should not need to use more than a very tiny amount, like less than 0.1% w/v (or so) of the whole liquid volume - based on the concept of CMC at which the surface tension reduction plateaus.

Critical micelle concentration (CMC) - OpenWetWare

openwetware.org

Any more after that simply goes in formation of more/bigger micelles in the bulk of the liquid without any benefit to the surface. There may be some other effects of adding larger amounts. It is significantly more viscous liquid than your typical sensitizer so adding a lot of it will increase the overall viscosity of the sensitizer. It can presumably also act as some form of a binder. What do these do to the print - could be good or bad, so use accordingly.

:Niranjan.

 

[Andrew O'Neill]

I am seriously thinking of going back to the original Cyanotype formula. I was getting consistent results with it. The new cyanotype is finnicky. I'm givin'er one more go this evening.