Please use PNG format for clarity. The system automatically adjusts image size but we suggest using a 1:1 ratio square image to design, as this is consistent throughout our sites.
You should take into account when designing your comp cards, that when adding features like 'instant wins' and 'cash alternatives', they will appear as top left overlays on your images on the individual comp card page. Also, for the landing page, all comp cards will have a countdown timer at the bottom, which will slightly overlay the bottom section of the image.
Please see the below images for further clarity:
