A blueprint is, literally, a blue-colored print that is made by overlaying a black sketch over a sheet of specially treated vellum, plastic or paper. Architect and engineers use them to make copies of plans. Did you know it's extremely easy to make the paper yourself? All it takes is a little chemistry know-how. Here's what you do:

Blueprint Paper Materials

• 15 mL of 10% potassium hexacyanoferrate(III) (potassium ferricyanide)
• 15 mL of 10% iron(III) ammonium citrate solution
• petri dish
• white paper
• tongs or small paintbrush
• small opaque object (e.g., coin, leaf, key)

Make Blueprint Paper

1. In a very dim room or in the dark: pour the potassium ferricyanide and iron(III) ammonium citrate solutions together into a petri dish. Stir the solution to mix it.

2. Use tongs to drag a sheet of paper across the top of the mixture or else paint the solution onto the paper using a paintbrush.

3. Allow the sheet of blueprint paper to dry, coated side up, in the dark. To keep the paper from being exposed to light and to keep it flat as it dries, it may help to set the wet sheet of paper on a larger piece of cardboard and cover it with another piece of cardboard.

4. When you are ready to capture the image, uncover the top of the paper and overlay an ink drawing on clear plastic or tracing paper or else simply set an opaque object on the blueprint paper, such as a coin or key.

5. Now expose the blueprint paper to direct sunlight. Remember: for this to work the paper must have remained in the dark until this point! If it's windy you may need to weigh down the paper to keep the object in place.

6. Allow the paper to develop in the sunlight for about 20 minutes, then cover the paper and return to the darkened room.

7. Thoroughly rinse the blueprint paper under cold running water. It's fine to have the lights on. If you do not rinse away any unreacted chemicals, the paper will darken over time and ruin the image. However, if all the excess chemicals are rinsed away, you'll be left with a permanent colorfast image of your object or design.

8. Allow the paper to dry.

Cleanup and Safety

The materials for making blueprint (cyanotype) paper are safe to work with, but it's a good idea to wear gloves, since you'll be working in the dark and might otherwise cyanotype your hands (turn them temporarily blue). Also, don't drink the chemicals. They are not particularly toxic, but they are not food. Wash your hands when you are done with this project.

How Blueprint Paper Works

January 29^th marks the passing of Fritz Haber. Haber was a German chemist who discovered a process to create ammonia from atmospheric gases. The Haber-Bosch process is a reaction that fixes nitrogen to form ammonia (NH₃) from nitrogen gas (N₂) and hydrogen gas (H₂) under pressure over an iron catalyst. Haber discovered the process on a laboratory scale using table top equipment. German chemical engineer Carl Bosch converted the laboratory equipment to be used on large scale industrial equipment. This process was important in the production of agricultural fertilizers to replace the guano industry of South America. During World War I, the process was important to Germany for the production of munitions and explosives.

The process would earn both Haber and Bosch Nobel Prizes in Chemistry (1918 and 1931 respectively). Today, the Haber-Bosch process accounts for 100 million tons of fertilizer per year. Find out what else occurred on this day in science history.

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My son says my car smells like candy. This is not because I satisfy some sugar craving while driving, but because I waxed it with the same wax used to coat many candies. This is carnauba wax, also known as palm wax or Brazil wax, which comes from the leaves of the Copernicia prunifera palm grown only in Brazil. The wax is obtained by beating the wax off of the dried palm fronds and then refining it for use.

Carnauba wax consists of fatty acid esters (80-85%), fatty alcohols (10-16%), acids (3-6%) and hydrocarbons (1-3%). It is around 20% esterified fatty diols, 10% methoxylated or hydroxylated cinnamic acid, and 6% hydroxylated fatty acids. Carnauba wax has a very high melting point of 82-86 °C (180-187 °F). It is harder than concrete and nearly insoluble in water and ethanol. It is non-toxic and hypoallergenic. The combination of properties leads to many applications, including use in food, cosmetics, automobile and furniture wax, molds for semiconductor devices, and as a coating for dental floss. You use products that contain carnauba wax every day, though you may not have known what the ingredient was or where it came from. It is one of those extremely useful natural chemicals and renewable resources that doesn't have a synthetic equivalent. As for my car smelling like candy... the wax does have a distinctive sweet scent. It might be more accurate to say many car waxes and candies smell like carnauba wax.

Where Does Candle Wax Go? | Candy Chromatography

Have you ever experienced a chip pan fire or other kitchen grease fire? This photograph actually is a simulated chip pan fire, produced as a demonstration. I have to wonder if the simulation was intended to be that spectacular. Also, I bet that fire was pretty intriguing to people passing by the lab outdoors.

Chip pan fires reportedly are the most common cause of house fires in the UK. A chip pan is a deep metal pan filled with oil used to fry chips (french fries). A fire can start if the oil gets too hot and ignites. Overfilling the pan or adding wet chips can cause oil to overflow the pan and catch fire, too. If you add water or wet chips to the pan, the water sinks to the bottom of the pan. The bottom of the pan is hot, so the water vaporizes. The water vapor expands, forcing the oil out of the pan (which can splash you with hot oil even if it doesn't cause a fire).

Back to that photograph... If you feel like setting your own lab on fire by trying the simulation, here's how to set it up. You fill a metal beaker with wax, heat it over a Bunsen burner until it catches fire, then add a little water to the beaker (presumably from a distance). This also goes to show, dramatically, why you don't want to try to put out a grease fire with water.

State of Matter of Fire | Less-Dangerous Fire Projects