Thermocromatic Sinatra Shirt In Uncategorized by Jayarr CustomsDecember 16, 2009 So basically the way this shirt design work is like this: When the wearer’s body is below 90 degrees the design on the left is how it will look. When its above 90 degrees the image of Sinatra will disappear and his tie will turn red. I want you all to know this isnt a concept shirt , i will have a fully functional sample printed by this weekend so if you have any interest in seeing it in action come by the shop!