Before you write about a commission
Studio engagements typically begin at USD $X,000. It is on the page so no one spends a call discovering the numbers were never going to meet.
The three commissions and a full case study are on the Studio page. If one of them is obviously yours, say which — it saves a round trip.
If you are pitching an essay
Read two things in the Library first and tell us which. The house does not commission on subject alone; it commissions on whether the writer has a body in the argument.