Backspacers by Allan are a handmade accessory designed specifically to suit the IKEA Kallax. It stops your records from being pushed too far back inside  the cube and keeps them looking even and tidy. 
 
Keep your records to the front and perfectly in line with Backspacers by Allan. They are hand cut from the finest of materials and fit precisely into each cube. Just affix at the bottom back of each cube using the included industrial strength double sided adhesive.  Then, slide your records in front and they'll be flush with the front of your shelves.  Beautiful!