Concrete reasoning involves the ability to analyze information and solve problems on a literal (concrete) level. We use concrete reasoning when we think through and solve hands-on problems. Concrete reasoning tasks involve skills such as: Basic knowledge of names of objects, places, and people.
I have been using a standard 8 wide by 10 height format, and try to fit my fonts and graphics into that area, thats on large and xl shirts, you can inch upward or backward from there. don't be afraid to experiment.
1 The right chest can accommodate a design or name/title and for best visual results, will be centered with the logo sewn on the left chest.  Above the seamed cuff of a short sleeve sports shirt or woven shirt is an excellent choice for a logo or company tag line.