We recommend your JPG file size: - 800 x 800 pixels if you are uploading small designs like logos, icons, business cards etc
or - 1000 x 1000 pixels if you are uploading larger designs like web, brochure, poster designs etc
This preview file is only used around the DesignCrowd site to display your design to the customer and only needs to be large enough to display correctly when the user clicks to view larger version (otherwise it will be usually scaled down to a thumbnail size of 300 x 250).