For vertical and overhead installations, such as installation into walls, cathedral ceilings, and rafters, as well as floors to be insulated from below, Oregon Shepherd offers a fabric netting which may be stapled to wood framing to hold wool in place during installation.
This fabric is somewhat like a synthetic quilt backing and comes in 10-foot wide swaths.
Some folks choose to source something locally, such as bird netting, or even used bedsheets from the local thrift store.
If one orders by the exact square footage needed, this may result in the cutting and piecing together of many smaller pieces of fabric, and depending upon your specific project, it may be more efficient to order by linear feet. For example, if you have 100 linear feet of walls that are 9 feet high, you might want to order 100 linear feet of fabric (1000 square feet instead of 900) and thus discard a one foot strip.