What is aspect ratio? 

A "locked aspect ratio" means the proportional relationship between the width and height of an image or shape is maintained when resizing. If the aspect ratio is locked, changing one dimension (width or height) automatically adjusts the other dimension to preserve the original shape. This is the reason why we only require you to choose the height of your image/logo. One way to test out what size you need is to physically print out your logo at home on basic printer paper. Cut out your image and use gentle tape to affix it to the front of your product. This will give you an idea of your measurement. We also provide single sample stickers for you to evaluate size.