A lot of people I talk to tell me that they won't buy tees online because they just don't know what type of quality they will receive. That is understandable. You don't want to go throwing away your hard earned on junk and we have all heard horror stories.
I thought it would be interesting to show people some shirts that have been washed multiple times so I went and dragged a couple of clean ones out under the camera for you. These are both from Threadless and I purchased them last year. Not too sure of the exact dates but they have both been around for a while.
My tees don't exactly get pampered. They are washed in the machine then either chucked in the drier or hung up. I don't have an outside washing line so they are hung up inside. This means mine will not be as faded as those that are hung out in the sun. I am not sure how many times these have been washed (I wasn't keeping count) but it is at least 30 times each. (conservative estimate)
As you can see these are both a bit faded but I like that. It gives them a nice vintage look. You can see the things that people worry about like cracking, peeling etc just have not happened.
The best piece of advice I can give you if you are thinking of purchasing tees online for the first time is to stick to big well known stores. Many independent brands use well known printers for their apparel so you are safe there as well. You can easily do some research. You are likely to run into trouble on sites like Ebay and similar. As a general rule of thumb if the brand does not have its own website you need to be a little careful. The exception to this are the large competition sites like Threadless, Teefury, Designs By Humans etc. or the POD (print on demand) sites like zazzle, redbubble etc. Many designers / artists use these type of sites when starting out. These are large sites with good reputations that stand by their products.
I hope this has helped you. Now all you have to do is choose which shirts you want out of the millions available.