Prester John
: I also meant to add my experience to your earlier question about horn as a cover material.
The weather here rarely drops below 0C/32f, with wet winters, and hot dry summers with usually a lot of days around 30C/85f, and a handful of days each year getting up to around 42C/108f. Although I have felt tiny dimensional changes over the time I’ve had the horn Guardians knife, and my golden Ox horn Lambsfoot knife, both of them are currently perfectly flush, as they were when they were new.
All I’ve done to treat them is apply a bit of mineral oil according to the old woodworkers’ rule of “once a day for a week, once a week for a month, once a month for a year, and once a year for life”.
Now, if I happen to have mineral oil left on my hands after oiling another knife, instead of wiping it off with a rag, I just wipe it on one of my horn handled knives.
I was quite surprised to hear of some of the drastic dimensional changes. I’ve taken a pic of my horn covered 2017 Guardian knife with an old horn handled Bunny knife with a known provenance, for comparison purposes. (Sorry, Jack, I don’t have a horn covered Lambsfoot that old.) I guess it’s 60s-70s era, so say it’s about 50 years old, and has probably not been carried and used regularly for at least 15 or 20 years. I doubt if the handles were ever oiled. There’s definitely been shrinkage of the material, but even so, on the mark side, you can see it’s fairly minimal. In fact, I’d venture to say, if it had been moisturised by being carried and used regularly in that time, the horn would be pretty close to the original dimensions.