T-shirt Printing dpi question

[Carable]

Hi everyone! This may be a silly question, I'm hoping someone can help me out. As I'm looking through t-shirt designs, I'm finding some differences in dpi. I work in photoshop myself (I'm a digital scrapbooker), and I usually work in 300dpi for the best print quality. Yet, most of the clip art on the internet and disigns I've gotten are 72 dpi, which look good on a computer screen but print out rather blurry. If they are small enough (like a tag or autograph pages) then it isn't a big deal, but I'm worried about a larger graphic for a t-shirt. Most of the finished products that people post look great. Does anyone have any tips you can share with a newbie?

 

[RustManFan]

PB displays images in web size like 72 dpi but they do store the original. I create all mine as 300 dpi and when you download, rather than save, you get the original size. One I most recently posted is 2550 x 2588 pixels with a 300 dpi. I believe some DISigners aren't creating theirs as 300 dpi like I am