This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Practice Work. Making blue prints, especially where you buy the paper already sensitized, is a very simple process, as the paper is printed in bright sunlight and is developed by merely washing in water. The principal interest in this process lies in the sensitizing of your own paper, as the sensitizing bath may be applied to fabrics, or any other surface, and prints made just the same as upon paper. See following chapter.
365. As this process is quite simple, you will experience little or no trouble. Be sure and print in the sun. The appearance of the print during printing is faint and mealy, similar to a platinum. Print until all outline is visible. A few experiments will enable you to judge the proper depth. It is advisable to note on the back of the prints of your first efforts, all the data connected with the experiments, which file for future reference.