Oh, yes. The postcard. I ordered a bunch of fountain pen ink from one of my favorite brands of ink, Birmingham Pen Company, and they like to include ULTRA-THICK postcards as a thank you. You may or may not see another one in one of Joe’s mail call videos. If memory serves, the writing is in red ink. That would be Montblanc James Dean Rebel Red. It would have been fitting to actually use a Birmingham ink, but I opted for the only thing I could afford in a Montblanc store. (Their cheapest fountain pen was $250 on sale!) Also worth noting, it was purchased on the way back from Arizona.
Chemistry & Jackson Pollock? Yeah, I suppose that scans as a theme. :D 
Currently in the earholes: 
Oh, yes. The postcard. I ordered a bunch of fountain pen ink from one of my favorite brands of ink, Birmingham Pen Company, and they like to include ULTRA-THICK postcards as a thank you. You may or may not see another one in one of Joe’s mail call videos. If memory serves, the writing is in red ink. That would be Montblanc James Dean Rebel Red. It would have been fitting to actually use a Birmingham ink, but I opted for the only thing I could afford in a Montblanc store. (Their cheapest fountain pen was $250 on sale!) Also worth noting, it was purchased on the way back from Arizona.