This is my first try of cyanotype.
Palace at Warsaw taken at 2013.
Note from wikipedia :
Cyanotype is a photographic printing process that produces a cyan-blue print. Engineers used the process well into the 20th century as a simple and low-cost process to produce copies of drawings, referred to as blueprints. The process uses two chemicals: ammonium iron(III), citrate and potassium ferricyanide.