Do you have any 2×4 bricks in wild colors with unusual letters on their studs? If you do, you just might have a treasure from LEGO’s historic quest to improve the quality of its bricks back in the late 1950s-1960s. German LEGO fan Beryll Roehl (aka Fantastic Brick) enjoys collecting and artfully photographing such test bricks. We found Beryll’s pictures so impressive and intriguing that we reached out to her for an interview. Get ready for a fascinating and colorful journey into the wonderful world of test bricks!

TBB: Hi Beryll, and welcome to the Brothers Brick! Can you tell our readers little bit about yourself?

Beryll: Sure! I grew up in the late 1960s, so I come from the generation that built LEGO models with the few types of basic building blocks that were available. I currently live in small village in northern Germany with my three adult sons…and their LEGO bricks! Careerwise, I studied mathematics and art and currently work for a school in the special education sector.

TBB: Could you tell us why you collect test bricks and how you became interested in collecting them?

Beryll: Although several years have passed since my childhood, I have never lost my passion for LEGO. Once I had children of my own, I would take them to the flea markets and we would look for LEGO toys. On one fateful visit, I made an unusual discovery in a large LEGO collection for sale. The seller had 2×4 building bricks that looked like LEGO bricks, but they had strange letters on their studs and came in extraordinary colors. I had never seen these before.

TBB: That’s an amazing flea market find! How did you learn more about these bricks?

Beryll: Thanks to the internet, I found other people who collected such bricks and later learned they were test bricks manufactured for LEGO by the chemical company, Bayer. I reached out to both Bayer and LEGO, but most of my questions didn’t lead anywhere. Official documentation was not available, and neither party was able to tell me very much.

Giving up was never an option, so this marked the beginning of my detective work that has continued into the present. In particular, I find inspiration in the stories told by former Bayer and LEGO employees, as well as their relatives. Some of these individuals still have test bricks stashed away in their attic or cellar.

TBB: It must be nice to have such an insider perspective. Do you consult any other sources for information?

Beryll: Yes. Over the years, a small but wonderful community of collectors from around the world has formed, and we have collectively unearthed many different types of test bricks. In fact, we learned that there were other companies making test bricks besides Bayer, such as BASF, DSM, Borg Warner, and Grangemouth.

TBB: After so many years of collecting, you must have accumulated a wealth of knowledge on these unusual bricks. I have a feeling many of our readers have never heard of Bayer test bricks before but would love to learn more. When it comes to the history of LEGO, what is the significance of Bayer test bricks?

Beryll: Early LEGO bricks were made of cellulose acetate plastic, which has a tendency to warp over time. From the late 1950s through the 1960s, LEGO began searching for a new type of plastic to replace cellulose acetate. It was decided this new plastic would have to be resistant to warping, rigid but flexible, and colorfast. Another goal was eliminating the use of cadmium, which had served as a pigment for the yellow and red bricks.

German plastics-suppliers Bayer and BASF were called in to help, and LEGO gave them some of their older molding machines and 2×4 brick molds to get started. The earliest test bricks had the old LEGO logo on the studs, and you can find them in beautiful non-production (for the period) colors and from a variety of plastic mixtures. This next set of champagne-colored bricks was made by Bayer.

Eventually, LEGO decided to go with ABS (Acrylonitrile Butadiene Styrene) plastic, which is still used today. After ABS was selected, the next step was determining the optimal clutch power (grip) needed for each LEGO brick. Four versions of 2×4 bricks were made, each one with slightly different stud diameters. These bricks were distinguished by the letters embossed on their studs: A, B, C, and D. Brick A had the tallest studs but the weakest clutch. Brick D had the tallest studs and strongest clutch.

Ultimately, brick C was chosen as the new standard. Bayer produced test bricks with a letter “C” on all eight studs, bricks with a “C” on seven of the eight studs, and square test specimens. All of these presumably came from a single mold. In fact, there is a picture of it in a magazine produced by the chemical company in 1990. The accompanying text reads, “Diverse specimens – including a plate, a rod, a square, and bricks – are produced by the LEGO group to test requirements such as toughness and fracture resistance so ‘that the studs on top connect well.’ Only colorants that meet specific purity requirements may be used.” Below are some examples of Bayer’s square test specimens.

LEGO also apparently commissioned Borg-Warner and DSM to do test bricks and other test specimens. Since these companies are based in the U.S. and Netherlands respectively, C bricks can also be found in those countries.

I have discovered many different LEGO Bayer test bricks over the years. For example, I have found bricks with studs featuring a small “f” and those with a big “F” (These bricks were most likely used to test a different tube design). There are also bricks with a “G” on seven studs and a number on the eighth, as well as bricks with the more modern-looking LEGO logo on the studs. These were produced in some extraordinary plastics and special colors.

In addition to Bayer, there are unusual and interesting test bricks from other chemical companies, such as BASF and Borg-Warner (The bricks “hatching” from the egg were made by BASF). However, outlining which types were made where would go beyond the scope of this little interview. If you want to know more feel free to join our small community on Flickr!

TBB: What inspired you to photograph test bricks with real-life objects? How do you pick items to photograph alongside the bricks?

Beryll: I try to find objects which convey the character of each brick’s plastic and coloration, such as the following examples:

Beryll: Then there is this picture with “Willy,” the house spider, which raises the question as to whether or not there are ugly colors.

TBB: Those are nice! I spent some time browsing your images on Flickr and really liked the picture of the test brick with the snail. What is the story behind this photograph?

Beryll: I didn`t choose the snail; the snail chose me! She happened to be hidden in the flower and suddenly appeared on the brick.

TBB: I heard you would like to do a book on Bayer test bricks. Are you planning on writing a book? If so, would you like to tell us more about that?

Beryll: This is an idea that has been around for a long time in our small group of collectors. We’ve been gathering information, stories and bricks for a long time. As of now, there are still too many unanswered questions to fill in the gaps of this area of LEGO history.

TBB: I see, Beryll. In that case, I hope some more people will come forward with more information to help you with your research. Thank you for taking time to share your love of test bricks with our readers. Your photographs are amazing, and we can’t wait to see what you share next!