Dress like a professional without paying for a professional fee to do it! The Signature Series Umpire Shirt. Signature Series combines quality, performance and lightweight construction to give you one of the best offering in the officiating marketplace. Tested on-field by some of the world's best professional umpires, is the choice for the beginning umpire or the seasoned veteran alike. You won't find a tougher shirt on the diamond. Has the Illinois IHSA logo above the pocket and the IHSA Official logo on the left sleeve.