Rigger
The person who does the tying in a rope scene, also called the rope top. Some practitioners question the word because rigging is also a qualified trade, but it is now the usual term.
A rigger is the person who puts the rope on, as opposed to the rope bottom, who is tied. Shibari Study’s glossary notes a debate about the word, since rigging is also an occupation with formal qualifications, yet in rope it has become interchangeable with rope top. Anatomie Studio adds that some people prefer “rope top”, and that the term should not be read as “dominant”, which suggests a more formal power exchange. Someone who enjoys both tying and being tied is a switch. Japanese terms for rope teachers include nawashi and bakushi. More in Both sides of the rope.