"Using a UV source, such as the sun, make delicate contact photographs and photograms using old or fogged silver gelatin paper. No development required!"
Explanation taken from: AlternativePhotography.com
I do love lumen prints and photograms by the way. It never stop to amaze me how the image is layered on the photo sensitive material. It's alchemy, a bit of magic and expectation.
Even if the image lacks of something deeply appealing I love it anyway. But as an artist simply capture an image it's not enough most of the times; I love to build images using photographic media for it as a source to exploration, a facet that fortunately have been nurtured for great teachers like Heliumen Triana, Esteban Gutiérrez and off course my great master Omaira Abadia.
Each lumen print (or contact photography or photograms, still dealing with the names) was scanned before and after the fix process. then were manipulated in Photoshop as part of the exploration.
I explore more about it in my blog, and also write some of my thoughts about this translation from the analogical to the digital and the compulsion inherent to the photographic act.