Lay your chair upholstery fabric over the foam side of the template you created, setting your fabric so that lines or patterns run in the correct direction and are centered.
Carefully turn the fabric, and foam covered template so that the fabric is face down on a clean work surface.
Run a bead of glue along the most detailed cardboard edge of the template.
Carefully glue the edge of the fabric to the cardboard template, making sure it fits tightly around any curves. Use the flat end of a glue spreading spatula to smooth out any curves and press the fabric into the glue.
Pull the fabric tight on the side opposite the side you have glued. Run a bead of glue along the cardboard template and glue the second edge of the fabric in place, making sure the fabric is stretched over the foam on the front side of the cushion , and that the fabric pattern and grain continue to line up correctly. If your fabric needs adjusting, pull it free of the glue and line it up correctly.
Trim any excess fabric, leaving approximately 1/4 inch glued to the cardboard.
Set the cushion aside to dry