If you want a truly secure WiFi network then you have no choice but to resort to measures such as using one of those very long passwords consist of letters and numbers. This adds an extra point security, but sometimes the problem is just remembering this password or share it with friends or colleagues at the office. A Reddit user thought a quick fix: turn your WiFi password in a QR code and then print it out and hang it on the wall in a visible place:
From here, anyone interested in connecting to the wireless network only has to use a QR code reader on your smartphone to get the password quickly. If you think the idea good enough to apply in your case here that have created a website where QR code is generated automatically. Just go here to the form, enter the data and press the 'Generate QR Code WiFi', then save and print the generated image.