Letterpress printing does not always have to begin with metal type.  If you have a fragile type you don't want to wear out, if you want to use a computer-generated font, if you have a large amount of type to set and your composing stick hand is tired, you can use photopolymer plates.  Above a student in a Depot workshop is washing out the plate after it has been exposed. To see the whole process check out Tom Parson's pictures on Flickr  https://www.flickr.com/photos/79988210@N00/sets/72157647162502923/ or call him to schedule an individual workshop 720-480-5358.