OK, time for another go at improving on these cyanotypes. Instead of using a small syringe to dispense the sensitizer onto the paper, I used a small eye dropper. This made putting the sensitizer onto the paper a lot easier and I ended up with much more even distribution. This becomes pretty apparent once the sensitizer has dried.Next improvement was to increase the exposure time. First two exposures were 8 and 20 minutes - this one was 70 minutes! I kept an eye on the colour of the paper around the outside of the negative and it really didn't darken down much more after about 20 minutes, but I left another 50 minutes just to be sure.
While the print is darker than the 20 minute print from yesterday, it isn't that much darker although it does have more in the midtones. I am going to have to look at other alternatives for improving the dMax than just simply increasing the exposure time.
You will find a straight silver print from another negative from the same series here. These Type 55 Polaroid negatives were very contrasty (which was why I picked them for these experiments).
It is winter and the weather is overcast, so the amount of UV in the atmosphere is going to be fairly low. Maybe a suntan lamp (which is UV based) would produce better exposed prints. The exposure would certainly be easy to control.
Other than that, there aren't a lot of other options. One option is to use more appropriately exposed and developed negatives. An experiment for another day.....
