Every now and then I manage to get involved in some interesting investigations. Recently I had one such project that allowed me to use a little wood science and technology to help authenticate some Woodstock relics associated with the original stage.

I've watched several documentaries, listened to hours music from Woodstock, and I've leafed though countless iconic photos, including this one below showing Richie Havens opening the festival singing Freedom. One thing that most people wouldn't pay much attention to in the photograph is the plywood sheathing that was used to construct the stage. The plywood is distinctly painted and has large black triangles with lettering below each one. This past December I received a phone call from a client that was interested in having me authenticate what he claimed were those exact same panels shown in the photo below.

Photo 1 - Richie Havens opening at Woodstock. Stage is constructed with plywood panels that have distinctive paint markings and black triangles.

As the story goes, my client attended Woodstock, lived in the area at that time and actually knew people that helped assemble the stage. Money was tight back then and some workers were compensated with the construction materials at the conclusion of the event. Fast forward a few decades when my client, on a hunch, decided to investigate one of those locations where he knew some of the plywood from the original stage was used for a couple of projects. Low and behold, he found what he was looking for. Now he just needed a little wood science and technology to help him authenticate the panels in his possession.

Since the plywood would have been constructed back in the late 60s, I had to do some ground work. I reached out to some colleagues at the APA - The Engineered Wood Association and Weyerhauser. Turns out the APA actually uses the Richie Havens photo in some of their technical presentations! Immediately I knew I was off to a good start.

In summary, here’s what I found:

1. My client brought some plywood samples and I was able to inspect them. I identified the species of the plywood as Douglas-fir which is consistent for construction plywood.

2. The dark triangles were definitely Weyerhauser symbols.

Photo 2 - Authentic DFPA plywood grade mark consistent with the time frame of Woodstock on one of my clients plywood samples.

3. One of the plywood samples had a fairly legible grade mark. That grade mark is a certified APA grade mark indicating “Tested DFPA Quality”, “Standard” grade, "Exterior Glue", and a span rating of “48/24” which are shown in Photo 2 above. The APA certification marking observed on the sample became effective November 1, 1966, as prescribed by the voluntary product standard, PS 1-66. Example grade stamps from PS 1-66 are shown in photo 3 below. This type of grade description did not exist pre-1966. All this to say, the grade mark on the plywood sample is indeed consistent with the time frame of Woodstock.

Photo 3 - Example DFPA plywood grade marks intiated in 1996 per PS 1-66 (Provided by the APA-The Engineered Wood Association).

3. Finally, provided in Photo 4 below is another plywood sample in my clients possession. This sample is painted consistent with the panels shown in the Richie Havens photo above.

Photo 4 - Painted plywood panels consistent with those shown in Photo 1.

Therefore, based on all my observations, including the species of the panel samples, a review of the standard PS 1-66 for plywood that became effective November 1, 1966, and of course the painted panel sections, as well as all the Weyerhauser stamps clearly visible right behind Richie Havens, it certainly appears to me that the plywood is authentic and from the Woodstock Festival and the original stage!