Category Archives: Retro Reflective Paint Articles

Reflective Paint versus Reflective Tape – The Difference

Retro reflectivity is often used to make an object more visible at night.  This simply means that when made retro reflective, the object collects light from a source, and returns it back to that source more than it returns it anywhere else.  More specifically, the object returns much more light than what surrounds it, creating what we know as contrast, and contrast is the reason we see individual objects.

reflective tape versus reflective paint

On the surface, the difference between a paint, an adhesive film, or a hard reflector may seem obvious.  All end up on the surface of an object, create retro reflectivity, and make it more visible at night.  But a closer look at the products reveals distinct differences that separate uses and applications.  One simple example is the idea of making a rock in your front yard reflective to approaching traffic at night.

It would make sense that a rock or series of rocks that run along a road would need to be visible to approaching cars for both safety and liability reasons.  A reflective application of some type would solve this problem.  A solid reflector could be glued to the surface.  Pieces of reflective tape could be applied.  Or the rock could be coated with reflective paint.

A solid plastic reflector would mark the rock, but would have to be glued on so that the reflectors face the oncoming car.  The reflector would show that something was there, however, it would not outline the object and show what it was.  So the car would just see a reflector.  This may or may not divert them away from the rock.

Silver Metalized Beads Reflective Paint
Reflective Paint – Silver Metalized Beads

Reflective tape could be adhered to the rock, but the issue would be how to get a sheet of reflective tape to conform and stick to a rock, given the uneven and rough surface.  So several smaller pieces would be needed.  If enough pieces were used, it may outline the rock, however, it would look strange, like a bunch of reflective band aids.  Another issue would be longevity.  The surface is not compatible with an adhesive product like tape.  So the life would be short.

road marker red

Reflective paint could be used to coat the entire surface of the rock, top, bottom, back, and sides.  If a grey paint was used, the rock would be very bright at night, but would look very much like just a rock in the daytime.  Also, since the rock has a rough, porous surface, a reflective coating will stick very well to it and last indefinitely. The downside to retro reflective paint would be that it only reflects a white color, whereas reflectors and tape will reflect other colors.

For a road surface, reflective tape may stick, but would not last very long.  Reflective paint will also stick, but will only be white, so if that is ok, it is a solution.  A hard reflector, like a raised pavement marker, would be best, in that it will last a long time, and reflects in colors.  It is actually made for that type of application.

For a sign face, a hard plastic reflector would work, but a sign needs to be covered in reflectivity.  A retro reflective coating would also work, but again, it would just reflect white.  So reflective tape, also known as sign sheeting would work best.  It can be CAD cut to make the letters, or used as a background with non reflective letters.

In summary, different surfaces and different applications require different types of reflective treatments.  There is not a one size fits all solution.  One solution will always be best for an application.  So reflective paint, reflective tape, and hard reflectors are not replacements for each other, instead they are tools that can be used to create night time visibility in almost any situation.  For example, on a tree, a hard reflector could be nailed in, or a circle of reflective paint could be used.  On a rock, reflective paint works best.  On a road, a raised pavement reflector is perfect.  On a sign where color is needed, reflective tape (sheeting) is optimal.  For parking lot logos, only a reflective paint would work.  And the list goes on.

History (Invention) of Retro Reflective Paint

This article outlines the history and development of Intermixed or Premixed Retro Reflective Paint from its beginning until the present.   To be intermixed or premixed simply means that the reflective elements are already in the solution, making application a one part or one step process.

What is Reflective Paint?

history invented retro reflective paintBefore we discuss the history of retro reflective paint, let’s talk about what it is and what function it serves in society. Retro reflective paint is a substance which is spread over a surface that dries or cures to leave a thin coating.  Reflective paint is different from normal paints in that at night it returns or redirects light that strikes it back to the source of that light.  This return of light makes the paint appear bright white to a viewer who is in line with the returning light.  For the viewer, this bright return of light contrasts the painted surface from the surrounding surfaces and objects nearby.  (When you see a street sign at night that it illuminated by your headlights, you are experiencing the same effect.)

Note – Reflective means to return or bounce light, and retro reflective means to return light back to its source.  A mirror is reflective, and reflective paint or reflective sheeting is retro reflective.

History of Reflective Paint.

As stated before, there are two main components for reflective paint.  One is paint, normally clear, and the other would be glass spheres or beads.  There are other components used in the paints, however, these are the main ones.  Paint itself was invented thousands of years ago, however, perfectly round reflective beads are not that old, and you need both to create retro reflective paint.  So before anyone could invent reflective coatings, they needed reflective beads.

history retro reflective paintIn 1914, Rudolph Potters developed a method for creating perfectly round glass spheres that would reflect light back to the light source.  He found that by dropping hot molten glass, it would form an almost perfect sphere as it fell.  So he developed a controlled way to produce perfectly round beads.  His patent was for the method of creating glass spheres, and the apparatus or machinery needed for the process.  This was an important invention and revolutionized the safety and traffic industry. From this invention came reflective road lines, reflective tape, movie screens, reflective clothing, and more. In 1941, he patented his invention. From that time until now, Potters Beads has filed for about 100 patents. The first patent in the glass bead field was titled the “Method and Apparatus for Producing Glass Beads“.

history of reflective paintOnce Rudolph Potters and his brother Paul formed Potters Beads and began mass production, several inventions and patents that utilized their invention quickly followed. The reflective movie screen was one of the first inventions or applications.   You have most likely heard the term “silver screen” when referring to theaters.  This term came about because in the 1910’s, movie screens were coated with a reflective paint that gave them a silvery appearance. The screens reflected light back towards the camera and the audience, giving a better experience.  The beads used for these screens were Potters Beads.  So the first real mention of a reflective coating or paint being used in commerce would have been for movie screens.  At that time, the actual reflective paint used to coat the movies screens was invented, but not patented.  An official patent of a reflective coating would take place years later for an entirely different application.

reflective road paintOverwhelmingly, the largest application for reflective glass beads is in the highway safety market.  Reflective glass beads are used all over the world in massive quantities to make painted road stripes and thermoplastic road stripes reflective.  And because lines wear away, the demand is never ending.  So from the beginning, for the most part, road striping reflectivity is what the beads created by Potters Beads have been used for.  As a side note, to create a reflective road stripe you simply put down a layer of paint or hot thermoplastic, apply glass beads to the surface where they form a bond and remain exposed, and you have a bright reflective line that can be seen day and night in dry and wet conditions.  There is no way to count all the lives that have been saved by this invention and its application in the road striping industry.

Note – Potters Beads remains the oldest and largest producer of glass beads in the world.

In the late 1930’s and 40’s, a company called 3m became very interested in retro reflective traffic products. If you look at their current product offerings in this area, you can see that their interest paid off.  Many people know that 3m invented what we now know as reflective tape or sheeting for traffic signs, however, what some do not know is that this product came from an effort to create reflective road stripes.  The product they first attempted consisted of glass beads embedded in an adhesive film that could be adhered to the road.  It worked, however, longevity was an issue so the idea for using this invention for road stripes was shelved.  It was not a total loss however, because the concept led to the creation of retro reflective sheeting in 1941, an invention that literally changed the world of night time driving.  But 3m was not at all done with trying to invent a reflective road striping product.

invention of reflective paintAs previously mentioned, up until the late 40’s, road stripes were made reflective by first applying a layer of paint, and then going over the wet paint with glass beads.  This two step process is often called the drop on method and the beads are referred to as drop on highway beads. This method was used in the very beginning and is still used today.  The beginning of the development of retro reflective paint relates to the desire of inventors to take the two steps of the drop on method and combine them into one step.  This seems fairly simple, however,  as with any process or invention, there were problems to solve.

Note – the problem that inventors were trying to overcome was the tendency of glass beads to sink in a solution and not stay on the surface.  Because to reflect, glass beads need to be exposed on top of the painted surface so that light can enter and be returned.

In 1949, the 3m company developed and patented a paint that premixed glass beads in with paint.  The product would be sprayed onto a road surface and when dry, would create a reflective stripe.  The patent was named “Highway Marking Paint Containing Glass Beads“.    Since glass spheres were all the way through the layer of paint, as the lines wore, new glass beads would be exposed so that reflectivity was maintained over time.  This invention and method can be known as an intermix method versus a drop on method where the paint is applied first, and then beads to the surface.  The invention worked, however, the drop on method has remained to this day, the most popular way to create reflective road markings. This patent expired in 1968.

Note – reflective paint inventions were working, however, they did not reflect as well as simply dropping beads on wet paint.  Because of this, they did not meet highway standards.  An excerpt from a subsequent patent explains why.  It is as follows –

In the United States patent to Heltzer, No. 2,574,971, dated November 13, 1951, Highway Marking Paint Containing Glass Beads, the glass spheres or beads were incorporated in the paint and the paint and the glass spheres applied together in a single stage. The paint film above the beads of this composition is worn away to expose the tops of the beads and in this manner a reflex reflective surface is developed through wear. The durability of the reflex reflective action, although somewhat improved, does not provide the high standards of nighttime visibility for adequately long periods of time.

history invention reflective paintIn 1956, another reflective paint was invented by American Marietta.  This invention was simply called “Centerline Paint“. This invention would use what is called Specular or Mirror reflectivity instead of Retro Reflective Glass Spheres.  Reflective crushed glass was mixed with paint to create little mirrors in the surface that would reflect light back to car headlights.  Crushed glass also created a non skid surface, whereas glass beads created a potentially slippery surface when wet.  This patent expired in 1975.

In 1958, American Marietta updated their invention of reflective road marking paint to include larger glass spheres in their paints.  This added brightness to the invention while maintaining the non skid characteristics of the line.  This invention or patent was named “Road Marking Paint“.  The patent for this invention expired in 1978.

invention retro reflective paintIn 1966, 3m created yet another reflective paint that they initially called “Reflective Coating Compositions Containing Glass Beads, Metal Flake Pigment and Binder“.  This was probably the most creative iteration of this product in that it added components to both increase reflectivity, and add color to the coating.  This was accomplished through the use of colored metal flakes that were smaller than the glass beads.  Once applied, and while still in a liquid form, the flakes would settle behind the beads and offer a colored reflective background.  Also, higher index beads were used for this product.  This product was different from previous ones in that it was intended to be used by sign makers who wanted an easy one step way to create a sign background.  For example, if a bill board needed to be seen at night, certain elements of that sign could be made reflective so that oncoming traffic would see it.  This is done today with larger rolls of self adhesive reflective sheeting.  The patent for this product expired in 1983.

history development reflective paint coatingsIn 1977, 3m filed for a patent referred to as a “Retro-Reflective Liquid Coating Composition“.  The patent was granted in 1982.  The invention was unique in that it was a gel type coating or paint.  The gel consistency kept the beads in suspension, and the solvents in the coating caused the mixture to dry quickly.  When it dried, the coating formed little domes or mounds on a surface that were instantly retro reflective.  These raised reflective domes or mounds provided retro reflectivity at more angles than a standard flat surface.  The stated purpose of the invention is as follows – A coating composition useful, inter alia, to form mound-shaped retroreflective marks that rapidly actuate photo scanner sensing devices. The patent for this invention expired in 1999.

As far as can be determined, there are no active patents for reflective paints, and since every conceivable way of creating it using glass beads has been exhausted, there most likely never will be.  In other words, reflective paint is in the public domain and has been for decades.

With that being said, there are many reflective paints available on the market today. Some are spray aerosol, some are liquid and brush (or roller) applied, and others are in the form of inks that are applied by the silk screening process.  Some common uses are  small scale projects like crafts or hobbies, bicycle reflectivity, personal safety (garments), dog collar visibility, parking lot logos, odd shaped object marking (reflective), and much more.

In almost all cases, the goal of the application of retro reflective paint, is night time safety through visibility.  And for the most part, this occurs in automobile traffic where the lack of night time visibility can be fatal.  So although attempts to replace the drop on reflective road striping method did not pan out as expected, reflective coatings are very much a part of modern day personal safety, just in different applications.  Reflective paints and Reflective Sheeting (tape) both serve to light up the night, and keep people safe.

For more information about reflective paints and tapes, read our article on Reflective Paint versus Reflective Tape.  And as always, if you have any questions, feel free to contact us using the contact link to the left.

How Do I Apply Reflective Paint for the Brightest Effect?

How To Apply Retro Reflective Paint (click to shop)

Applying reflective paint is similar to applying any paint with two key differences.  First, the paint must be shaken and stirred very well so that the beads are evenly distributed in the container.  If you don’t mix well, the top layer will just be clear polyurethane. Second, the coats of paint must be thin.  Thick coats will result in the beads sinking below the surface.  Beads below the surface will not reflective.  For beads to reflect, they must be partially above the surface.  So thin coats allow for this.  Multiple coats can be applied, however, the first coat must be dry before the second coat is applied.  And remember, the last coat must be thin.

how to apply reflective paint
Applying Reflective Paint

For the brightest effect, you can purchase a pack of reflective powder, and then while your coat of paint is still wet, sprinkle the powder over the top and let it dry.  This will give you the brightest and most reflective coating possible.  Use silver or metalized reflective powder for our silver paint, and white reflective powder for our standard whit reflective paint.

Silver Metalized Beads Reflective Paint
Reflective Paint – Silver Metalized Beads

How Durable is Retro Reflective Paint?

Is Reflective Paint Durable? (click to shop)

Retro reflective paint made with Clear Water Based Polyurethane is very durable both inside and out.  Because of its tough characteristics, Polyurethane based coatings last a long time in rugged outdoor conditions.  They also bond well to surfaces, assuring that the reflective properties will last for years.polyurethane reflective paint

Water based Polyurethane coatings are compatible with more surfaces such as cement, rocks, wood, etc.. because of it’s ability to soak into the surface and harden.  Oil based coatings tend to sit on top of these surfaces and will later sheet off.


Different Types of Reflective Beads and Their Purpose.

Various Types of Reflective Beads (click to shop)

Reflective glass beads come in different types and sizes.  Bead size is measured in microns or mesh size.  A 50 mesh bead (297 microns) for example would be used for making traffic paint reflective.  The larger beads sit up higher in the paint and reflect at sharper angles.  Large beads come in several types with standard  AASHTO beads being the most common, and FAA spec airport beads being the most specialized and the brightest.  Traffic or paint beads are distributed on top of wet paint rendering it retro reflective.  Traffic beads are why you can see road lines at night.

reflective retro glass beads
Glass beads for traffic striping

For applications such as reflective paint, reflective tape, or reflective garment trim, small beads are used.  These are normally 300 mesh and above in size.  Note that the higher the mesh size, the smaller the bead.  And the lower the micron size the small the bead.  Small beads are often referred to as reflective powder because of their powder like consistency.  Because they are small, they mix in with a liquid clear base and stay in solution longer than larger beads would. They also work better for making reflective tapes. Reflective powder beads are why you can see road workers and road signs at night.

In summary, larger reflective beads are generally used on highway lines to make them brighter at night. They are dropped onto wet paint.  Small microscopic beads or reflective powder beads are used for making reflective fabric, reflective tape, and reflective paint.


How is Retro Reflective Paint Made?

How is Reflective Paint Made? (click to shop)

Retro reflective paint is made by intermixing clear polyurethane paint with either white standard glass spheres (beads) or silver metalized glass spheres (beads).  To help keep the beads in solution, an anti settling agent can be also be used.  The purpose of the clear polyurethane is to bond the beads to the surface of the object being coated.  Exposed beads that sit higher than the paint surface are what provide reflectivity.  To enhance this effect, we use plenty of reflective powder in our paints.

make reflective paint

Because glass beads are heavier than liquid polyurethane, the beads tend to sink to the bottom of the container over time, so when you are ready to paint, the container should be shaken, and then stirred.  I normally stir, then immediately dip my brush in and paint.  This assures a plentiful supply of beads in the coat and an even distribution over the surface.

It would seem that the thicker the coat, the better, however, the coat actually needs to be thin so that beads are exposed through the top of the layer of clear.  This allows light to enter the microscopic beads, bounce off the back, and exit the way it came.

Silver Metalized Beads versus Standard White (clear) Beads

Silver beads, which are dark in color, actually reflect at twice the intensity that white (clear) beads do.  This is because the metalized finish of the silver beads gives them a mirror backing which reflects light much more efficiently.  Reflective Paint made with metalized silver beads in preferred for applications where a bright return of light is required.

silver reflective paint
Silver Reflective Paint

White beads do not have a metalized coating, so they appear to be white in color, although they are actually clear.  Light enters these clear beads and reflects, but just not as intensely.  Reflective Paint made with clear (white) glass spheres is preferred when a more clear or white coating is desired and reflectivity does not need to be as intense.

White reflective paint
White Reflective Paint

In summary, retro reflective paint is made by mixing a clear medium like polyurethane with microscopic glass beads, either silver metalized, or white standard.  The beads that are exposed take in and return light back to the source, hence making the paint reflective.

Viziglow reflective paint

What is Retro Reflective Paint?

What Is Reflective Paint? (click to shop)

People often ask what reflective paint is and how is it different from standard paints. Reflective paint and retro reflectivity in general can be a little confusing to understand, but it’s based on very simple scientific concepts of light refraction. In this article I’ll cover what reflective paint is, and how it works. First, let me say that reflective paint is technically “Retro Reflective” because it returns light back to only the source of that light. A point we will cover in this article.

White reflective paint
Reflective Paint with White Standard Beads

What Is Reflective Paint?

Retro Reflective paint is regular paint with retro reflective qualities. As previously stated, when something is retro reflective it simply means that the object returns light back to the source only. This is different from say a piece of colored paper or a mirror which either return light everywhere or back to a single spot. Returning light everywhere is called Diffuse or Scattered reflectivity, and returning light back to a particular spot depending on angles is called Specular or Mirror reflectivity. You will have examples of both of these types of reflectivity in your home. What you may not have however, are examples of retro reflectivity.

specular mirror reflective
Specular or Mirror Reflective

How Does Retro Reflective Paint Work?

All retro reflective paints have one thing in common, that is that they all use micro glass spheres to achieve reflectivity. Glass beads capture light, bend it, and send it back to the light source. Hence the use of the term “Retro”. Reflective paints utilize glass beads in two ways to achieve a retro reflective effect.

glass bead reflective paint

First, glass beads can be intermixed with a clear base. Polyurethane clear is what Viziglow uses because it is outdoor durable. For an intermixed paint to work, the coating has to be thin so that the beads are exposed to incoming light. Beads that sink below the surface will not reflect. So it is critical that coats of reflective paint be thin. This method produces a nice bright reflective coating.

Second, glass beads can be sprinkled on top of either a clear or colored base. This normally results in quite a few beads remaining on the surface, exposed to incoming light. Once the paint dries, the beads will remain on the surface and should not come off. Using this method, the coating does not have to be as thin, since beads will be distributed on top of the layer and should not sink. This method produces an incredibly bright reflective coating.

Silver Metalized Beads Reflective Paint
Reflective Paint – Silver Metalized Beads

So in summary reflective paint is a coating that returns light back to the source, and this coating does this using glass spheres that collect and bounce light back to where it came from.