With most stock photo agencies now offering a library of vector images, the possibilities are endless as far as what you could do with the image if the right license is available. If you are looking to print some t-shirts, you will need to review the licenses before you purchase to ensure that you can legally use the image in this way. The great thing about vector images is that you can edit and customize the art to personalize it just the way you want.
If you need software to manipulate your vector graphics, you might want to check our guide to download Adobe Illustrator for a very low price, and even for free!
As explained on iStockphoto, you cannot use the images on t-shirts if you plan to sell them with just a standard license. If you purchase an extended license, you can have the right to sell them, but the quantities are limited. If you are using the image for personal use, and not on t-shirts for sale, you are permitted to print up to 499,999 of them.
Vexels.com is a very interesting place to get T-shirt designs because they actually create Royalty-free t-shirt designs to sell shirts and merchandise. When you subscribe you get access to thousands of print-ready t-shirt designs with the Merch License to sell on Merch by Amazon, Redbubble, Etsy, and other print-on-demand platforms, as well as on your own t-shirt online business made with Shopify for example.
At Dreamstime, there are various different licenses that you are allowed to choose from for each image. It actually appears as though buying the exclusive rights to some vectors is fairly inexpensive. You will need to review all the terms for each type of license based on whether you want to print on t-shirts for personal use or if you want to be able to sell the t-shirt. Selecting the right license is important to keep you from legal action.
Other websites that provide vector images include VectorStock, 123rf, Pixmac, Shutterstock, Vector Portal, Fotolia and so many more. There are so many places to go to search for that perfect image; you shouldn't have a problem finding exactly what you are looking for. If you find your perfect image in a rasterized form, you could consider using Photoshop or applications such as Vector Magic to convert your image to vector.