Secure the future of your photos with this smart frame insert A problem with all frames that arent made to measure is that their backing boards contain acid which makes your picture turn yellow and become brittle over time This kit contains a PH-neutral cardboard sheet that you can easily place between your picture and the picture frames backing board to prevent the acid from penetrating the picture You can then rest in the knowledge that your picture will remain beautiful for many years to come Dont forget that all our custom-made frames already have acid-free backing boards so dont need to be supplemented with acid-free inserts