Choose a conductive material such as aluminum foil, copper mesh, steel mesh, or a metal box
Make sure the enclosure is fully continuous with no gaps, holes, or open seams
Overlap all joints and seams so the conductive surface stays unbroken
Seal seams with conductive tape or metal tape
Use a conductive lid or cover that makes full contact with the enclosure
Keep any openings smaller than the wavelength of the electromagnetic signals you want to block
Place the item you want to protect inside without letting it touch the cage walls
If using a box, line the inside or outside with conductive material and ensure all sides are connected
Grounding is optional for many uses, but connect to ground if your application requires it
Test the cage by placing a radio or phone inside and checking for signal loss
Avoid insulating gaps, painted contact points, or nonconductive barriers between metal parts