If you want your cushion looks puffy ,please choose Inner size Bigger than cushion Cover 3-5Cm. Cushion Core size 35X35CM is better fit for cushion cover size 30x30cm Cushion Core Size 40X40CM is better fit for cushion cover size 35x35cm Cushion Core size 45X45CM is better fit for cushion cover size 40x40cm Cushion Core size 50x50cm is better fit for cushion cover size 45x45cm Cushion Core size 55x55cm is better fit for cushion cover size 50x50cm Cushion Core size 60x60cm is better fit for cushion cover size 55x55cm Cushion Core size 30x50cm is better fit for cushion cover size 25x45cm Cushion Core size 40x60cm is better fit for cushion cover size 35x55cm Cushion Core size 50x70cm is better fit for cushion cover size 45x65cm "