How to Develop a Photo Using Blueprint Paper and Windex




Introduction: How to Develop a Photo Using Blueprint Paper and Windex

Develop blueprint paper using Windex.

Step 1: Grab a Container

Order some take-out and rip the lid of the styrofoam container.

Step 2: Fill With Windex

Pour adequate amount of Windex glass cleaner into container lid.

Step 3: Rack

Find something that you can set your paper on so it doesn't get wet but still absorbs the Windex fumes.

Step 4: Plastic Bag

Place inside plastic bag so the fumes are contained.

Step 5: Grab a Print

Find a nice black and white photograph that you will use for the contact printing.

Step 6: Diazo Paper

You will need some blueprint diazo paper. I found mine on ebay for six dollars.

Step 7: Stack Them

Place the blueprint paper sensitive side up on a flat surface. Then place the black and white photo face down.

Step 8: Sandwich

Sandwich with a piece of clear glass.

Step 9: Expose

Place in DIRECT sunlight for 4 to 5 minutes.

Step 10: Check Paper

After you have exposed for 4 to 5 minutes you should see some discoloration that resembles your image.

Step 11: Develop

Place paper sensitive side down on the rack in plastic sack for 5 minutes or more. Make sure to close the plastic bag so the fumes stay in.

Step 12: Done

Enjoy your Windex print.



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36 Discussions

No good... the colour change is due to the amonia in the Windex interacting with the areas of the blueprint paper that were _not_ exposed to the sunlight. Amonia + whatever chemical makes blue.

I'm a building designer. To clarify and a little general history of the process and the term "blueprint" and another term for your vocabulary "whiteprint" and this processes. The commonly used terminology "Blueprint" came from an older process of making prints largely for architecture and engineering. This process is technically called "cyanotype". This was a different process than the above. It was also known for being a 'wet process' due to the fact that it is developed under water after exposure. The process of coating the paper is inherently wet to some degree for both cyanotype and diazo process. The diazo paper like above is just pre-coated in a factory instead of you having to do it yourself. The old cyanotype during its use was almost always had to be coated on a watercolor paper or similar substrate by the architects/engineers because having the paper pre-coated was not that common in those days. Cyanotype used two chemical solutions (potassium ferricyanide and Ammonium Iron (III) Citrate), each dilluted from powder in water (usually distilled water). This process was rather time consuming as you had to coat the paper, wait for it to dry (usually doing something else constructive during that time) and you expose it. This exposure time would be similar to traditional diazo process that used the sun or other UV light source. Then you do the wet development process which often involved a water based wash and then a short period of time in a bath of water mixed with a cap or few caps full of hydrogen peroxide for some extra oxidizing kick and then back in the plain water wash for a maybe 30 seconds or so and then set to dry. The dry time was time consuming. You had to use either an ultra-fine woven fabric or a watercolor paper that will survive the time in water. This process creates a print where the background is blue and the areas where the lines of the drawing (black inked lines, normally, on the original vellum drawings) be white. The "blueprints" where essentially a photo negative copy of the original drawings.

Eventually, as time went on, a new process of making architectural/engineering prints using the diazo method. This method uses a photo emulsion coating made from diazonium salt and azo dye. By the mid-20th century, pre-coated diazo paper was normal and easily available. The diazo process is what one may call a 'dry' process. This is because the development cycle is rather dry, not requiring the paper to dry. This combined with the paper being commonly pre-coated and able to be ordered much like you can do today but via mail order or telephone order, allowed for some significant time saving by the architects/engineers. Technically, diazo prints as above is a "whiteprint" but people still call it blueprints in the general sense. In the 1960s and 70s and into the 1980s. specialized machines that semi-automated the process of exposing and development were developed. These machines are often called "Blueline machines". A nickname for diazo prints of technical drawings were called 'blueline prints' as diazo prints produced photo positives of the original drawings where the lines of the architectural/engineering drawings being blue. Diazonium salt / Azo dye photo emulsion when exposed by the alkaline environment that ammonia (and Windex that contains ammonia) would turn blue. This is why the diazo copy is blue. Diazo process can be manually done without a fancy "Blueline" machine as the above article proves. The more transparent the paper of the original drawing (or in some cases, original drawings inked on clear mylar (like acetate sheets), the faster the exposure would be and shorter time in the sun. The Ammonia used in those blueline machines were of rather high concentration like 15% to 25% or higher concentration (basically industrial concentration). Hence development times in seconds compared to minutes. This is why it became popular and replaced cyanotype. Even with a more manual method above and household ammonia, the time saved by using diazo method is still considerable compared to the older cyanotype. The biggest negative of diazotype is the inherent obvious odor of ammonia.

Architect/Engineers saved time in some areas in order to spend more time in other areas allowing for more service and addressing more complex issues in architectural/engineering design. I love the diazo process with only one exception... the odor of ammonia. I still love cyanotype but it is a lot more time consuming to make several copies of entire sets of building plans that can easily be 15 to 25+ sheets. Sometimes a lot more than 25 sheets for each copy. When you consider that you probably have to make 5 to 8+ sets. 2 or 3 copies for the building department requirements, a copy for the client and additional copies for contractor and sub-contractors. The time that diazo prints takes to produce is efficiently time-managed under the manual process can be under a half hour.

Another trick to speed up the ammonia development time is actually to heat up the ammonia (or Windex) to about 130 degrees F or even 150 degrees in a pan that you can heat up. While pure ammonia turns to gas at -28 degrees F. but at 130 to 150 degrees, the dilluted ammonia in household ammonia concentration mix of 2% to ~3.5% is going to be somewhat slow to vapor off from the water base. At raised temperature, it goes through it faster. They even do that with blueline machines where the ammonia vapor is heated as it fills the 'development' chamber of the blueline machine so that it minimizes the time needed for the paper as it passes through the development chamber. The key is not to heat ammonia to 212 degrees F because you are trying to avoid boiling the water base. Why turn the 'dry' process into a wet process? The elevated temperature would be able to trim minutes per sheet.

For a bit of clarification on this for others. Ammonia fumes are what make the blueprint paper change to blue. Anything, such as Windex in this case, that contains enough ammonia you can smell would work. An ammonia-free glass cleaner would not work. The stronger the ammonia smell, the faster it will develop. The anhydrous ammonia these papers are designed to work with is VERY strong, and only takes a few seconds to react.

To answer an old question here, there is nothing needed to "fix" the image. Once away from ammonia fumes, the developing stops. If not developed long enough, and any yellow remains, it will turn white quickly in light. Exposure to sunlight will cause the blue to fade though. It was pretty common for the top page of a set of blueprints on a jobsite to be pretty faded by the time the job was complete. Thus, cover sheets were common. You'd want to use a UV filtering glass if you framed one of these. Properly cared for, they last well. My dad's architectural firm archive has prints 50 years old that still look great.

Is there a way to fix the image once it is developed? In other words, how an you prevent it from fading when exposed to light?

To everyone above asking about changing the colour by adding dye/food colour &c. ,,, the blueprints aren't blue because of the blue windex ... they're blue because that's the blue in 'blue'print. The blueprint paper is what makes the image blue, not the chemicals. :) Therefore the blueprint.

 and that discoloration turns blue?

where can I get diazo paper to buy? So far no one seems to know what I am talking about.

1 reply

11 years ago

Does the black and white picture have to be on photopaper, or could I just print something from my laser printer and have the same effect?

1 reply

Yes. And if you want to be fancy when making your own contact prints, print on transparency plastic. Be sure to print a positive image.

The solvent in windex is ammonia. Everything else just makes it smell nice (and makes it blue).

What if we just used regular kitchen dye to change the color of the windex? would it possibly change the color of the picture?

The windex is not making the blueprint paper blue, it is merely a source of ammonia. Any household ammonia will work.

Yes, but it would take a very very very long time to give you an image. Check out

What about a stopbath? Lemon juice works for this.

Oh that just completely blew my mind. But can it be done with color photos?