I realize that I have strayed a little bit from the subject, but I wanted to provide background information that will lead to the focus of this article, which is how to make blueprints. I feel that the additional information is relevant to this articles focus.

The above process I described, whether a CAD print or a manually-produced drawing, yields what is called a "reproducible" or sometimes known a your "originals". These are produced on vellum or some type of drawing medium that allows light to pass through it. When someone uses this type of media for their originals (also known as a reproducible), they typically intend to make a blueline blueprint. Meaning, a print that is actually bluish in color with darker blue lines than the blue background. Hence, the word "blueprint" was born. With that said, please note that a drawing on bond media cannot be copied via the blueline process. If a drawing on bond media is to be copied, one would need a large format Xerox machine, known as "large format copiers". There are multiple manufacturers that produce large format copiers, such as Xerox, Oce, K&E, Kip, and a few others. These copiers that are for making "copies of copies" and work well but will not make the blue drawing (blue background with darker blue lines) that I previously mentioned.

How Blueline Machines Work Ever wonder about blueline machines and how they work? Let me repeat myself and state that the basic difference in a "blueline machine" and a "large format copy machine" is that blueline machines will only make a copy of a reproducible document such as vellum sometimes known a "trans-bond" or any material that will allow light to pass through it. This is not the only difference, but its the most noted or would be considered the fork in the road, where the two types of machines split.

Blueline machines all rely on the ability to pass light through the document that you are wanting to copy therefore the document you are making a copy of must have enough transparency for light to pass through it. I know this can be considered a negative for blueline machines, however, blueline machines make BLUE prints, not the black and white copies one would get with a large format copier. And, blueline prints are very impressive since they are blue and show off your work nicely. I know many old-timers and small architectural shops that don't like to use the large format copiers since they only do black and white. And, I have seen many shops that have both machines, a blueline, and a large format copier and use either depending on the desired results. Blueline machines use a diazo process and diazo paper that comes wrapped in a thick black plastic bag that is sealed to keep the light from exposing the paper. Most diazo paper is yellow in color when it comes out of the sealed bag, then turns blue when it has been ran through a blueline machine. The process that works to expose the paper is done with black lights and ammonia. Keep reading, we will explain more about this process and how blueline machines actually work.

The Actual Process of Making Copies of your Documents Once you have your original documents ready to copy, plenty of diazo fresh unexposed paper on hand, and your diazo machine ready to go, you can begin to make your blueprints. Remember, your originals must be of some type of transparent medium, such as vellum, or trans-bond. You start with one original drawing and hold it up, and then place one sheet of diazo paper on top of it and match all edges so the two sheets appear as one. Then, you start feeding these two sheets into the machine into the lower roller section, the two will become exposed to ammonia and a black light and they will both come back out of the machine as the machines powered rollers slowly take the paper in and back out of the machine itself. When the two come out of the machine, you will then peel away your original and lay it aside. Then you will take the diazo paper and run it back through the machine on the top roller section. Please note that most diazo blueprint machines have a bottom roller and a top roller. You can continue to run the diazo paper through the top roller process over and over, several times depending on how new your ammonia is, the speed at which you exposed the first run when both sheets were held together, and how blue you want your print to become. It's an easy process and one you will perfect quickly, only after making a couple of blueprints. You will do this same process for each sheet in your drawing set, if you have multiple drawings to copy. Once all of your copies are made, some people run a single sheet of diazo paper through the machine without any original drawing in front of it, which exposes the entire sheet and makes the entire sheet a very dark blue. This sheet is then used to cut into slivers of paper the same height as your drawings, but only wide enough to make three folds in it, which makes a nice binder that you can staple on one end of your drawing set. Usually three to four staples with a heavy duty staple gun is all that is needed to secure the binder and hold your drawing set together.

Long Machine Life The diazo process is inherently simple; the copiers have relatively few complicated parts and their maintenance is inexpensive. Most diazo copiers remain in use for well over 20 years with a high degree of reliability and little down time.

Low Cost Per Copy Diazo copiers use readily available diazo-coated papers, vellums, and films, which are priced competitively with so-called "plain papers". The aqueous ammonia developer used by most diazo copier systems is low in cost and environmentally safe. Aqueous ammonia is nothing more than a stronger solution of clear household ammonia. Further, because the "brains" of the system is built into the paper or other media, the equipment itself requires little maintenance. There are no per-copy or click charges with most diazo copiers. They are very reliable pieces of equipment that provide years of useful life with little down time.

Ammonia is a completely natural substance It is a basic building-block substance, which is crucial to life on our planet. It is composed of only two elements - nitrogen and hydrogen. Ammonia is produced by all animals, including humans, as a natural product of the metabolic process. Each person generates about 550 grams per year. According to one source, 500 families release more ammonia each year than 20,000 diazo copying machines. Ammonia is a natural product that poses no long term health hazard when used properly and is no threat to the environment. Ammonia helps reduce acid rain; it is not one of the substances responsible for the greenhouse effect; it is not a known carcinogen; and, aqueous ammonia solution is not flammable. Ammonia is recycled by rain and soil in a process known as the "Nitrogen Cycle". Accumulation in surface water, soil, or in the atmosphere does not occur. This naturally regenerating cycle is vital to our ecology and life as we know it on this planet.

The diazo process produces no ozone or health concerns The diazo process relies entirely on natural substances to create high quality copies. There is no ozone, (a highly irritating poisonous gas) associated with diazo equipment. So-called "Sick-Building Syndrome" symptoms do not occur with diazo copiers, and all employees are safe from long-term health concerns. Dry diazo copying has reached a highly refined state of functionality. Diazo systems, by definition, require only natural substances for operations. The development process involves the release of only ammonia, moisture and heat energy. The diazo industry has integrated the exacting standards for ammonia handling, containment, and removal of nearly all ammonia odors. In addition, ammonia supply containers are safe and meet industry standard specifications. Hopefully by reading this document, you have learned more about how blueprints are made, the process, and the equipment that is necessary. Well known brand names of diazo type copiers are Rotolite, Diazit, and ReproTechnology.

About Author :
Rob is an employee at EngineerSupply.com and regularly writes articles on the AEC (Architecture, Engineering, Construction) Industry.