For a readable QR code, you have to choose a high contrast between foreground and background. i.e. : If you have a black foreground, best background will be white.
QR code with logo
When you put a logo in your QR Code, it can be more difficult to read. Choose a QR code with transparency to have a bigger logo and so a more beautiful QR Code design.
QR code's Size
Choose a QR code size accordingly to the distance of the reader : - For less than 5cm, you should print a 5cmx5cm QR Code. - Between 1m and 3m, you should print a 33cm x 33cm QR Code.
For a professional use of this QR code generator, you can contact us or buy it directly with Paypal. If you contact us, we will be able to help you to create your QR code design with logo. We can give you an API too, to generate a lot of QR codes with the same design.
QR code Margin
The QR codes margins are necessary to be able to read the QR Code. This QR code generator automatically calculate margins, don't change it to be sure that your QR code has good margins.