We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What are Blueprints?

Mary McMahon
Updated: May 16, 2024

Blueprints are prints made on a specially prepared substrate such as cotton, paper, or Mylar. The material on which the blueprints are made is coated with a light sensitive solution. When exposed, the solution sets into a dark blue color, leaving the unexposed portions white. The result is a traditional blueprint, also called a cyanoprint, a design in white against a blue background. Blueprints are used in architectural designs such as renderings for houses and ships, and the term is also used more generally to refer to a detailed and precise plan.

Contact printing is used to produce blueprints. First, a drawing is made on tracing paper, cloth, or another material which is transparent, allowing light through. The drawing is positioned over material soaked in a blueprint solution, and then exposed to a bright light. The resulting blueprint is chemically fixed and washed to remove chemical traces. It will be resistant to fading and marking, and is usually made on a durable material which can be rolled up and easily transported between offices and job sites.

The solution used to coat the substrate for blueprints is made from potassium ferricyanide and ammonium ferric citrate. It was developed by Sir John Herschal, a British astronomer, in the mid 1800s. The chemicals will react with bright light to form ferric ferrocyanide, an insoluble blue pigment. Potentially, numerous blueprints could be made from a master drawing and easily distributed, at a cost much lower than that of conventional photographic reproduction.

Modern advances in replication technology have allowed other techniques to replace the blueprint, although some firms continue to use blueprints for rendering. When marking up a blueprint, chalks in contrasting colors such as red and yellow are used, so that the markings are clearly visible. The edited blueprint is returned to the person who drafted it for the changes to be made, and then is printed again and checked. Once all parties are satisfied with the blueprint, it will be officially stamped, making it into a legal document which will be filed along with the other paperwork on the structure being built.

Drawing for blueprints and drafting in general requires training and skill. Good blueprints have crisp, clean lines and easy to read text, usually written in unadorned capital letters. High quality blueprints can look like a work of art, as they come from the hands of someone trained in technical drawing, and some building owners hang their blueprints on the wall as an artistic addition to the interior design.

HomeQuestionsAnswered is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a HomeQuestionsAnswered researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments
By jmc88 — On Aug 21, 2011

My parents recently had a small cottage built as a sort of private getaway. They got to have a lot of input on the design of the house. After it was all finished, the architect left them a copy of the cottage blueprints at their request, and I spent some time looking at them.

As far as their house went, doors and windows were indicated, but it wasn't specific enough to include outlets. I guess those are something that can be decided after the house is built. What it did have was a view of the house from the outside on each angle showing the various features.

It showed the finished outside as well as where the framing studs should be located. There were also various notes about different features. In the entranceway, they had special wood molding put in, and the blueprints even showed exactly how that should look.

At least from this experience, I could see a custom design taking several hours, and the blueprints can be very detailed.

By Izzy78 — On Aug 20, 2011

I have never seen a real blueprint in person. I have seen a few picture of them, but can't remember exactly what they looked like.

How detailed is a blueprint usually? Does it just have the basic floor plan with doors and windows and such, or does it go farther into showing exactly where the light switches and electrical outlets should be?

I was thinking, too, wouldn't a blueprint for a house have to be several pages? I would guess you would need a drawing for each floor, but then wouldn't you also need a vertical picture to show how tall the ceiling and windows were? Is there any difference between something like a garage blueprint and a home blueprint?

By matthewc23 — On Aug 19, 2011

@titans62 - My guess would be that there are a mix of techniques in use today. Like the article says, the paper is very durable and the print will never fade away. If you had a blueprint copied from a printer, there would be a chance of the ink fading or getting washed off in some conditions. Cost and convenience are probably a factor, too, since you would need a special printer and supplies.

There have still be a lot of advances in architecture. Now that we have computers, designers can use computer aided drafting programs to lay out a design, and look at the final product before printing. This is compared to the old system where someone would have to manually draw out an entire house.

By titans62 — On Aug 18, 2011

I don't know why I always assumed that blueprints were either just drawn onto blue paper or were printed on somehow. I didn't realize that blueprints had been in use for so long.

The article sounds like most companies still use the older process of making a design and exposing the special paper to light. Given our technology now, why don't they just print blueprints out?

In general, how much time goes into making something like a house blueprint? Surely it would depend on the architect drawing the design and the size and complexity of the house, but I'm just curious about a normal single family home.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
HomeQuestionsAnswered, in your inbox

Our latest articles, guides, and more, delivered daily.

HomeQuestionsAnswered, in your inbox

Our latest articles, guides, and more, delivered daily.