Beautiful and really appropriate artwork. You mentioned in another thread that the publisher connected you with an artist. Can you share, in vagaries if contrac

Beautiful and really appropriate artwork. You mentioned in another thread that the publisher connected you with an artist. Can you share, in vagaries if contractually necessary, the literal cost of this? Was it percent of revenue, fixed rate, a mix. Substantial (given you two would be the team), or more like a typical contracting affair?