customized flash cards

Small Card 55 x 85 mm (i. number of credit cards e. artist trading cards 'business card' size) 105 mm Square 105 x 105 mm; 148 mm Square 148 x 148 mm; Which size should I choose? A7 is the most popular flashcard size (1/8th of an A4 sheet) For something smaller (pocket sized), opt for Small Card instead For a square flashcard, 105 or 148 mm square are available