I suspect I am once again late to the party, but:

Two recent experiences: handled a friend's knife-fighter shoulder sheath in which the primary security was magnetic and lost a small knife sheath while mushrooming by putting it down on the leaf litter and duff next to my knee on a dark and rainy day [I looked and looked but the forest gods apparently accepted an offering I did not intend to make].

So, I need a sheath and I would like to put magnets in it to retain the knife. If I can figure out a relatively neat and economic way, I would also like to add magnets to several existing sheaths for various steel tools.

Thoughts?

Thanks.