Cyanotype

Another couple of cyanotypes made from digital negatives. The first image was printed onto Hahnemuhle proof paper, the second one onto Filiperson. The developer used was acetic acid at 1% solution to work in the midtones, then I left the images in a bath of hydrogen peroxide to increase the blue tones.

Cyanotypes from digital negatives

I've just set up a bulk ink system on my cheap Epson printer because I was fed up on spending so much money on cartridges. The conversion is relative simple to make and the guys from the shop repair said that sometimes it can be done while you wait. 

Once I got my printer running, I decided to print some digital negatives so I can make a few alternative process. The task isn't really easy when it comes to cheap inkjet printers... although the costs of my prints has been reduced drastically, having a bulk system which is not from the same manufacturer means that you can't easily make a color profile. I'm having a really hard time printing in black in my case, all my prints are coming with a dark blue tone.

I've decided to try some cyanotypes couple of days ago and they came out ok... I've lost some details on the highlights and the prints had to be left in a solution of 5% hydrogen peroxide (10% volume). 

All prints were made on Hahnemuhle proof paper with a solution of 3% gelatin (leaf) average 5 - 8 minutes on artificial UV light.

Cyanotypes

These are some of the results from a workshop I attended last month at Sesc in São Paulo about this great historic process called Cyanotype. For this particular work, we've used sheets of orthochromatic film inside homemade pinhole cameras. Ortho films are extremely high contrast making them a great choice for this process. 

The negatives were exposed to an average of 12 to 15 seconds as we had a bright but sunless day, they're later processed normally. We used filter paper to do these prints and they're brushed with a mix of equal solutions of potassium ferricyanide and  ferric ammonium citrate previously blended with water. In fact, one of the greatest advantages of this process is that  you can use any absorbent material that can be coated with the solution, like a piece of cloth or wood.

The results below were printed by putting together the negative and the filter paper like a "sandwich" on a glass support and exposing for 30 minutes in a artificial UV light box. The  prints are immersed in a sink with running water straight after to get the unexposed solution washed away and then let dry normally.

The workshop was ministered by Ricardo Hantzschel from the great Cidade Invertida project.

Below is the negative used to print the image above, note how contrasty the ortho film is.