2008 marathon tech shirts

[lenshanem]

Leana, I measured DH's ING tech shirt which is a medium and the Disney measurements you gave me were bigger so I guess I'll stick with the medium for him. I also put his on me and it was big, so looks like I'll stick with the small. Hope I did right. I want that shirt!

 

[greenmyvalley]

Pardon me, but what exactly is a tech shirt? I did a google search, and it looks sort of like a compression shirt, such as the type Under Armour manufactures. However, the shirts in the pictures in this thread look like standard long-sleeved tee-shirts.