Pretty good, glad I sized up
Wasn't sure about ordering a size up but glad I did, it fits way better. The organic cotton actually feels really good against the skin, not itchy at all.

Proton energy: small, positive, and the reason atoms have any charge at all — a graphic for the physics-minded who appreciate the building blocks most people never think about. Wear your favorite subatomic particle.
Printed to order on a soft 100% organic ring-spun cotton tee that keeps its shape and holds the print crisp.
GOTS & OCS certified organic cotton, PETA-Approved Vegan, sewn by a Fair Wear Foundation member. We don't print it until you order it — no overstock, no waste — and it ships free, usually 7–11 days in the US. Full sourcing record on our Product Transparency page.
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| Size | Length | Width | Sleeve |
|---|---|---|---|
| S | 27 ⅛" | 19 ½" | 8 ⅜" |
| M | 28 ¾" | 21" | 9 ½" |
| L | 29 ½" | 22 ¼" | 9 ⅝" |
| XL | 30 ¼" | 23 ⅜" | 9 ⅞" |
| 2XL | 31 ⅛" | 25" | 10" |
| Size | Length | Width | Sleeve |
|---|---|---|---|
| S | 69 cm | 49.5 cm | 22.5 cm |
| M | 73 cm | 53.5 cm | 24 cm |
| L | 75 cm | 56.5 cm | 24.5 cm |
| XL | 77 cm | 59.5 cm | 25 cm |
| 2XL | 79 cm | 63.5 cm | 25.5 cm |
Length: Measure from high point of shoulder to bottom hem.
Width: Measure across chest, 1" below armhole, laying flat.
Sleeve: Measure from shoulder seam to sleeve end.
Fabric: 5.3 oz./yd² (180 g/m²) • EU sizing - consider ordering one size up
Pretty good, glad I sized up
Wasn't sure about ordering a size up but glad I did, it fits way better. The organic cotton actually feels really good against the skin, not itchy at all.
So comfy, love it!
OMG, literally perfect tee.
Perfect gift for a science enthusiast!
My boyfriend is a huge science nerd and this was the perfect gift. He wears it all the time and says it's super soft.
My new favorite tee, second one from them!
This is actually my second tee from Design Delight Studio, and honestly, the quality just blows me away every time. I wore my first one until it literally fell apart (after like 3 years!), and this new 'Proton' design is just as good, maybe even softer. It's awesome knowing it's organic and ethical too; makes me feel pretty good wearing it, not just comfy. The fit is solid, but yeah, definitely size up if you're in the US!
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Virtually try on our certified-substrate apparel — GOTS organic cotton, GRS recycled polyester, OEKO-TEX Standard 100 — to see the perfect fit before you buy.
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Quick Answer
This is a Stanley/Stella STTU169 100% GOTS-certified organic cotton t-shirt, 5.3 oz/yd² (180 g/m²), unisex fit, printed on demand by Printful with water-based vegan inks. Stanley/Stella holds the GOTS, GRS, OEKO-TEX, and PETA-Approved Vegan certifications across the substrate. 30-day returns, free worldwide shipping.