When it comes to diorama building we tend to use a lot of commercial products, so to help you keep track of what I'm using I will usually make mention of it in the video and will often have a graphic pop up during the video to list the product.
For some videos that have a particularly long list of materials I might include that list in the video description here on my website.
A couple of example where I list the products can be seen here in
Realistic Scenery Vol.27, this was a sponsored video and many of the products were sourced from Woodland Scenics.
Another example of a video where I include extra details in the description is
Realistic Scenery Vol.10, in this video there is a lot of additional information regarding the specific dimensions of the bridge model, so as not to bore viewers by meticulously describing the length of every piece of cut wood I just add that info into the description.
So if you need to figure out what specific material was used, the best option is to take some notes while watching the video and possibly be sure to check that specific video description on this website, you might find the extra info there 😉