A background color just isn't enough? No worries, you can add any image background you like.
Optimal size is an image that can cover a desktop/laptop monitor display.
1920x1200 (or 1920x1080) should be sufficient.
Smaller resolution can also be applied, but expect some pixelation/blur when displayed on large screens. Remember to optimize the image for efficient load times. :)
How to insert Background Image:
Select your Flipbook
Go to Settings > Design > Branding
Click in the Pick image field next to Background
Upload / choose the image from the library
Press Save All
Should you want to add a color instead, you can just go to Colors below.
And now visitors can enjoy your Flipbook with whatever cool backdrop you chose!