Situations for using throwlines:
There are several techniques
Throwline The throw weight is a "beanbag" ranging from 6 to 16 ounces in weight.
Throwing cube or bag to hold the line. $25
Tree Climbing: Getting the Rope in the Tree - Tossing | CornellTreeClimbing
Getting the Rope Up Into the Tree | Terry Hale - The Weekend Woodsman
Attaching a heavy line to the throw line.
See Getting the Rope Up Into the Tree | Terry Hale - The Weekend Woodsman
Line Placement Gear - Tree Climbers International
Westech Rigging Supply - Rigging Equipment, Rigging Hardware, Tree Gear & Logging Supplies
How to Stuff a Rescue Throw Bag - YouTube