BUFF DAY THE 13TH Tee — Camp-Slasher Menace (Halloween Edition)
Horror × Hypertrophy. From the campsite to the squat rack.
BUFF DAY THE 13TH is our TSF take on a horror legend—mask on, traps out, and ready to take revenge on the weights. Gritty, high-contrast artwork that punches under gym lights and looks mean on the street.
Front print: Buff Day the 13th slasher graphic
Back print: Special Halloween edition “Buff Day the 13th” Iron Demon badge
Buff. Scary. Ready to rock the weights—just like us.
Print method: DTG for saturated color, softer hand, and better wash durability.
Fit & Fabric:
- Soft ringspun jersey, 4.2 oz / 142 g/m²
- Most colors: 100% combed & ring-spun cotton (heathers cotton/poly)
- Pre-shrunk, side-seamed, shoulder-to-shoulder taping
- Gym-ready stretch; built for training and street
Size & Notes:
- True to size for an athletic fit — size up for a looser pump fit
- Sizes S–5XL (select colors)
Care: Cold wash inside-out. Hang dry or low heat. Do not iron print.
Limited-season piece: Part of the 2025 Halloween Collection. No restocks.
THIS ISN'T
GYM MERCH.
IT'S A STANDARD.
Every shirt in this collection means something. Horror x Hypertrophy is the belief that the thing trying to break you is the same thing that builds you. You don't wear this because it looks good. You wear it because you hold the standard.
PACK REVIEWS.
Customer Reviews
Dope shirt to show off what Jason is doing on every day that isnt the 13th. Fits great and gets attention in and out of the gym.
