There is no standard collective noun for t-shirts.
Collective nouns are an informal part of language. Any noun that suits the situation can function as a collective noun; for example a display of t-shirts, a rack of t-shirts, or a wardrobe of t-shirts.
The noun 'committee' is a collective noun as a word for a group of people.The noun 'committee' is not a compound noun. A compound noun is a noun made up of two or more words that form a noun with a meaning of its own; for example, bathtub, hot dog, or tee-shirt.
Shoal is a collective noun. It is the collective noun for fish. A shoal of fish.The collective noun is a mint of candies
There is no standard collective noun for a group of reflections. The noun 'reflection' is not a standard collective noun.
No, the noun lumber is not used as a collective noun. The collective noun for lumber is a stack of lumber.
No, the noun farm is not a collective noun.
The collective noun is a series of explosions.
No, the noun land is not a collective noun. However, any noun can function is as a collective noun in a suitable context without being a designated collective noun.
No, the noun 'kin' is not a collective noun.
No it is not a collective noun.
No, games is not a collective noun. The collective noun for games is 'a compendium of games'.
The collective noun is an anthology of poetry.
The collective noun for 'wheat' is a sheaf of wheat.The collective noun for 'barley' is a crop of barley.