Personalized Irish St Patricks Day Letter M Monogram Youth T-Shirt. Irish Letter M Youth T-Shirt - Kelly Green alphabet gifts. Sure an this stylish St Paddy's Day monogram is just right for wearin' on St Patrick's Day, if your name begins with M. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.