Most pictures from your smart phone will work fine. If you have art or scan your art make sure you upload a .jpg or .png file. If you want part of your art to be transparent, you must use a .png file.The information below will be helpful if you run into problems, especially if you get your photo from other sources.
Image Size. (Mb) Make sure that you use a picture that is at least 1000 pixels on each side or more that 250kb. For best results upload a higher resolution picture up to a maximum of 5mb. The larger files will take longer to upload depending on your internet connection so be patient.
If you get an error message that your file is too large, you can reduce the size at http://www.imageoptimizer.net. Choose File to upload from your computer. Set to High quality, Max width: 2000 and Max height: 2000 and click Optimize Now. Then download and you are set to go.
Cropping. Any picture that you upload will automatically adjust to the frame size shown on the tee. This may not get you the best results. If a smart phone picture with default setting.is used, the picture will be long compared to the frame on a tee shirt. When the picture adjusts to the frame there will be a lot of distortion.
For this reason, make sure your picture is cropped to approximate the frame size.Just eyeball this when you crop and you will be fine. If you are using a camera or smart phone setting with 4:3 ration, there will be no need to crop unless you want a closeup picture. You can crop your photo for free at http://imageresize.org/