How to improve density in Cyanotypes?

[Fraunhofer]

I am quite happy with it Fumed silica is very fine silica dust (so don't breathe it in), I am sure Bostick & Sullivan sell it. Mine is from West Marine, they sell this as thickener for epoxies. And the one I had was left over from building my dark room sink.

 

[Fraunhofer]

The way this helps is that it traps your sensitizer very close to the paper surface, it prevents is from getting lost in the depth of the paper. It does work for most alternative processes which have a water-based sensitizer, also e.g. for Pd/Pt

 

[ChristopherCoy]

I am quite happy with it Fumed silica is very fine silica dust (so don't breathe it in), I am sure Bostick & Sullivan sell it. Mine is from West Marine, they sell this as thickener for epoxies. And the one I had was left over from building my dark room sink.

Sweet! I've got a West Marine two blocks away!

 

[ChristopherCoy]

I just found this little video. Is this what you do?

 

[nmp]

Example picture, made with fumed silica using Mike Ware's Simple Cyantope, medium contrast

That is a remarkable print.

I have some fumed silica...I am keeping it for when all else fails. Not very fond of handling it.

 

[Andrew O'Neill]

WOW! I'd be extremely happy with that kind of result.

It's VERY tricky to use, in my experience. So much so, I gave up on it. But that doesn't mean that you shouldn't try it.

http://www.alternativephotography.com/improve-your-siderotypes-with-fumed-silica-pre-treatment/

 

[ChristopherCoy]

It's VERY tricky to use, in my experience. So much so, I gave up on it. But that doesn't mean that you shouldn't try it.

http://www.alternativephotography.com/improve-your-siderotypes-with-fumed-silica-pre-treatment/

What makes it tricky?

 

[ChristopherCoy]

Mine is from West Marine, they sell this as thickener for epoxies..

This stuff?

https://www.westmarine.com/buy/west-system---406-colloidal-silica-filler-1-7-oz--318402?recordNum=2

 

[Fraunhofer]

This stuff?

https://www.westmarine.com/buy/west-system---406-colloidal-silica-filler-1-7-oz--318402?recordNum=2

Yep, that's it. I apply it dry with a foam roller and then just coat on it. You have to coat quickly with no hesitation and plenty of sensitizer.

 

[nmp]

That echos my experience. I also observed it took about 48 hours for the prints to reach their final state. This is probably quite dependent on environmental conditions.

That may as well be but that's just too long to wait to do a reading. That's why I started putting it in the oven.

 

[ChristopherCoy]

Yep, that's it. I apply it dry with a foam roller and then just coat on it. You have to coat quickly with no hesitation and plenty of sensitizer.

Sweet! I'm going to WM on my way home then!

 

[Fraunhofer]

I am sure they also sell foam rollers.

 

[ChristopherCoy]

I am sure they also sell foam rollers.

And because it's "bend me over West Marine", I'm sure they'll charge me $25 for the same foam roller that Home Depot sells for $3.97. (West Marine is famous in the boating community for being absurdly overpriced.)

 

[Fraunhofer]

I would probably apply this outside, especially if you live and work in the same space. Face mask is clearly indicated.

 

[Fraunhofer]

And because it's "bend me over West Marine", I'm sure they'll charge me $25 for the same foam roller that Home Depot sells for $3.97. (West Marine is famous in the boating community for being absurdly overpriced.)

Yes, indeed. I only bought one batch of epoxy from them, most expensive part of my sink.

 

[ChristopherCoy]

I would probably apply this outside, especially if you live and work in the same space. Face mask is clearly indicated.

I've got a stack of N95 masks at my disposal thankfully. We've been getting them for weeks now since we are first responders.

 

[ChristopherCoy]

I would probably apply this outside, especially if you live and work in the same space. Face mask is clearly indicated.

Have you ever coated your paper with fumed silica and let it sit, or do you coat it right away? I ask because I wonder if it would be ok to coat multiple sheets with silica and store them without chemicals applied for a while.

 

[Fraunhofer]

Have you ever coated your paper with fumed silica and let it sit, or do you coat it right away? I ask because I wonder if it would be ok to coat multiple sheets with silica and store them without chemicals applied for a while.

I do batch processing, but I have coated them usually within 24 hours. Maybe you just need to try.

 

[Andrew O'Neill]

What makes it tricky?

Brushing on the "correct" amount, otherwise you end up with a streaky mess. I could never make it work, with brushes or rollers. I've got a ton of fumed silica....apparently it's used in McDonald's milkshakes. Maybe I'll add some to a smoothie just to get rid of it...

 

[Fraunhofer]

The right amount is always less than you think, in my experience.

 

[Andrew O'Neill]

The right amount is always less than you think, in my experience.

Tried less....and less...and less. Wasn't for me. If you've got a good paper, it's not necessary.

 

[Fraunhofer]

Maybe I was just lucky, the paper is COT320, which is pretty good already. But in any case it's cheap enough.

 

[ChristopherCoy]

Tried less....and less...and less. Wasn't for me. If you've got a good paper, it's not necessary.

Even Bergger COT-320 doesn't do it for me. I found that it still didn't have the denisity/resolution that I wanted.

 

[ChristopherCoy]

Maybe I was just lucky, the paper is COT320, which is pretty good already. But in any case it's cheap enough.

I do have one question. Did you make the negative with a true negative, or with a dng?

 

[Fraunhofer]

This is from a 8x10 in-camera negative, developed to high contrast for alternative processes