Magiboards Solo Magnetic Sign Holder A4 Black (Pack 12) Solo Magnetic Paper Holder Window Display Frame has magnetic strips on the back of three of the borders which allows the paper holder to fix to any magnetic surface and also means that putting in the sheets and taking them out is a very simple operation. The magnetic border is approximately 10mm wide. The frames are slightly over sized to allow a complete A4 paper to be seen through the transparent part of the display frame.