"Powered by Condensation Nuclei"
Sure, it's a bit geeky - making a design about the particles that water condenses around to form clouds. It may confuse some people, but you'll get a good laugh from those who 'get it'.

For more details, click the "View Larger Image" link below.

click to view front / back: View Larger Color:

Condensation Nuclei Sweatshirt Powered By Condensation Nuclei (you know, the particles around which water condenses and thereby forms clouds!) A bit geeky sure, but so what. (poweredbytshirts.com) $25.99 Size:  Size Chart Small Medium Large X-Large 2X-Large (+$3.00) Color: White Ash Grey Qty:    AVAILABILITY: Product Number: 29869930 Tell a friend about this product! Product Information Fit: Standard Not too tight, not too loose. Fabric Thickness: Warm up in our stylin' Hanes Heavyweight 90/10 cotton/polyester sweatshirt. Thick (but not bulky), for maximum comfort and durability whether you're working out or hanging out. 10.1 oz. patented PrintPro® fabric in a 90/10 cotton/polyester blend Standard fit Spandex trim in cuffs and waistband