Baseball Uniform Customizer Custom Baseball T-shirts. By digital printing sublimation, Valkout Apparel always produces custom sublimation baseball uniforms. There is no minimum order requirement for our custom baseball uniforms, and there are no additional costs associated with adding player names, numbers, color, or any other decorations. We make custom sublimation baseball uniforms in all sizes for kids, teens, and adults. Custom sublimated baseball jerseys with a button-up, V-neck, or full button-down style are made by us. We typically use 100% polyester fabric with a 160gsm weight for sublimated baseball uniforms because of its moisture management and breathability.