Grafting Bands

For scion grafting these provide firmer more consistent hold of the joint and the rubber style stretch is much more user friendly across a range of temperatures than the taffy-like stretch of parafilm. These also last a season while parafilm only seems to last 1-2 months which may or may not be long enough for a strong enough graft union. You may want to inspect and manually cut the rubber band late in the season if it hasn t had enough weathering to naturally break.
Parafilm has uses other than binding the union, for example it is good for slowing moisture losses by pre-wrapping the whole scion(single layer), just the cut apex end, or over early summer t-buds. (The growing bud can break through a single layer of parafilm.) I just fount it inferior to this rubber for mechanically securing the graft joint.
For pencil thick scions I get a double layer wrap(out and back) out of one rubber band with a bit of care toward orderly wrapping.
Like pencil erasers or any other soft rubber, store them in a ziplock with the most of the air sucked