i would use a cold water wash for this item. is it one t -shirt or several? if it's one then i would use a mild washing detergent or dishwashing liquid, and soak it in cold water for a while; then wash by hand. if it's several i would use same mild detergent and a cold water, gentle cycle for laundering. using a gentle washing cycle is important in preventing the black from ruining the white of shirt.
My boyfriend has a T-shirt like that; white with 'embossed' black lettering. I always turn the t-shirt inside out to wash. It has been washed a few times now as it's one of his favourites. I'm not sure why, but the inside looks not so bright, but when it's turned the right way out it still looks good as new! I always was it on a 40 degree wash with light cotton-mix fabrics. I don't use any specific detergents.