Here is our list of backer veneers which could be considered ideal for balancing a panel to prevent warping. The JoeWoodworker website has an article discussing the use and need for backer veneer. Click here to learn more.
Other backer grade veneers can be found on our site by arranging the display order of veneers in a category using the "sort by" box at the top of the page. You can use the sorting menu to show the cheapest veneers or those which have the lowest grade. These are typically the best options for backer veneer.