There really are no limitations. if you can think of it we can print it! We can print variable names, dates, numbers, alphanumeric codes, barcodes, QR Codes, you name it. If you have a highly custom use and you are not sure if we can do it, please reach out to our Customer Support Team. Contact Support Team at Support@4over4.com or you can submit a custom quote request by using the Custom Project page https://www.4over4.com/custom-project