Bone or plastic?

[Killdeer]

If the scales show a gap at the bolsters, does that indicate they are plastic that has shrunk?

 

[riversidedep]

Not necessarily. It could have just been a poor fit to begin with.

 

[Danke42]

"Plastic" doesn't typically shrink. If you get it really cold it's going to contract but unless you have calibrated eyes you'll never know.

 

[Killdeer]

Is there a reliable way to identify bone scales in photographs?

 

[sceva]

Try blowing up the photos and looking for pores. Plastic (Delrin) always has a soft waxy look to mt.

 

[killgar]

What knife is it? Do you know the brand/maker?

Synthetic (plastic) handles can shrink as chemicals in the material dry out.

.

 

[Killdeer]

I have forgotten now whether it was a Camillus or Case Peanut, but the question is a general one. My present interest is in small, slipjoint knives, and my preference is bone or antler scales and carbon steel blades.

 

[killgar]

One "plastic" in particular that was used on old knives, and one you might want to be wary of is celluloid. As celluloid ages and the chemical composition breaks down it releases acidic fumes, known as "out-gassing". So not only can the handles shrink, but the gasses can eat metal, including steel.

This is not to say that people shouldn't buy or collect knives with celluloid handles, after all, they already exist, and they are going to do what they're going to do regardless, but the common advice is to not store knives with celluloid handles inside of anything that can trap the gasses (best to leave them out in the open, but not in sunlight), and, don't store them in close proximity to other knives, or anything else you don't want to be affected by the gasses.

But if you're specifically collecting bone and antler (stag) handle knives then you won't have to worry about celluloid. Unless you already have some with celluloid handles.

 

[Danke42]

My present interest is in small, slipjoint knives, and my preference is bone or antler scales and carbon steel blades.

You want to take a look in here.

Traditional Folders and Fixed Blades

Discussion of classic Hunters, Trappers, Lockbacks, Slipjoints, Skinners and other classic designs

www.bladeforums.com

Great Eastern Cutlery is the most desirable maker producing knives like you mention but you can really get in on the ground floor with makers like Case.

Here's a nice example of jigged bone from Case.

And here's chestnut sawcut bone from GEC (and tortise shell acrylic).

 

[tltt]

With bone, look for haversian canals. They are the tiny pores that housed blood vessels when the bone was alive. They look like little dots or lines in the bone's surface, you might need a magnifier, but it's usually easy to see them.