I need to have another batch of business cards printed and I have a design in mind. I can do the design work myself but I don't know the standard business card size. My current ones are 49mm x 87mm. I've measured some of the other business cards I have collected over the years and they all vary quite considerably in size. Before I can start to design my own one it would be beneficial for me to know the standard size, if there is one, or is it down to personal preference of the printer I use?