What If The Size Of My File Doesn't Fit The Template?

Preparing Artwork > General Questions
If the size of artwork is different than the size specified in the product template, then you should resize the selected image to fit the product template proportionately. To resize proportionately, hold the shift key down as you drag the corner points of the selected image making it bigger or smaller to fit the product template. If you do not resize proportionately, your artwork will look stretched and unprofessional.