So I actually went and researched the source and text of some of the original documents which mentioned the Picts and discovered that the quotes were but a small part, and once expanded not only confirmed that the Picts were tattooed, but described the process (they used sharp iron tools (needles?) and a natural plant-based ink called woad, which is apparently (in some forms) highly hallucenic by the way... sort of a very strong PCP type drug).
Most of the misquotes were taken from books 9 and 14 of the Etymologies of Isidore of Seville (560-636).
In the Chronica de Origine Antiquorum Pictorum (The Pictish Chronicle), an otherwise confusing text, he writes:
"Picti propria lingua nomen habent a picto corpore; eo quod, aculeis ferreis cum atramento, variarum figurarum sti(n)gmate annotantur."
"The Picts take their name in their own tongue from their painted bodies; this is because, using sharp iron tools and ink, they are marked by tattoos of various shapes."
Painted and tattooed!
When I bring this up to a very smug historian in the "Women of the Ink" documentary, you can actually see his proper British jaw drop.