London - Printing to Thick Card, A5 and Other Paper Types/Sizes
To print to card, A5 and other paper sizes you will first need to load the paper into the correct place on the printer. Special paper types (thick card, A5 and other sizes) should not be loaded into the printer paper drawers. Instead we'll need to use the printers "Bypass Tray".
Before starting you should note the size of your paper (e.g. A4, A5) and the "gsm" (or g/m²) of the paper, this number denotes the thickness of the paper and should be listed on the packaging of your paper.
Note: The printers have a minimum compatable thickness of 55 g/m² and a maximum thickness of 220 g/m².
Loading the paper
First we'll need to open the Bypass tray, on the right-hand side of the printer:


Next, load your paper and adjust the grey barriers:

Note: Gently push down the "loading flap" to make certain the paper is loaded correctly, this will ensure the paper is properly recognised by the printer:

Once you have loaded the paper, the printer screen will prompt you to select the type and size of paper you have loaded:

Using the information you noted at the beginning we can set these using the touch-screen interface. Most commonly the choices will be Plain 1, Plain 2, Heavy Paper 1 or Heavy Paper 2 - depending on the appropriate thickness. When you have selected the correct type and size of paper press OK.
Printing your document
macOS
When going to print first set your Paper Size as you selected on the printer (A5/A4 etc), then navigate down to Printer Options > Paper Feed then for All Pages From select Bypass Tray(PAPER TYPE) where the paper type matches your chosen selection on the printer. Set your other printing options and then you can print!

Note: If you are printing from Google Chrome, select More Settings > Open PDF in Preview and then print from there to access the extended printing options.
Windows
When going to print select Preferences

Under Main set your Original Size option to the paper size you are printing to. Then under Paper Source you will need to set you Output Size to the same setting. Set Paper Tray to Bypass Tray then Paper Type to the same type of paper that you had set on the printer.
Note: If you are printing from Google Chrome, select More Settings > Print using system dialog... (Ctrl+Shift+P) and then print from there to access the extended printing options.