"Cracked Ice" / "nu-pearl" etc. - celluloid or no?

[bleasure]

I've seen conflicting reports on these, but as I have several, I'd like to know for safekeeping's sake.

For instance:

49P no line Tuxedo
Syracuse utility jack (or whatever these are called)
4-line Sword Brand coffin bolster

Three different kinds of what look like roughly the same material. Would very much appreciate any definitive info

[bestgear]

I've seen conflicting reports on these, but as I have several, I'd like to know for safekeeping's sake.

checkout this post here to determine if they are celluloid: https://www.allaboutpocketknives.com/kn ... hp?t=57923

They aren’t showing any signs of off-gassing so I’d rest easy but keep them on a regular inspection cycle.

[edge213]

I've seen conflicting reports on these, but as I have several, I'd like to know for safekeeping's sake.

For instance:
PXL_20260120_002314165.jpg
PXL_20260120_002456834.jpg
49P no line Tuxedo
Syracuse utility jack (or whatever these are called)
4-line Sword Brand coffin bolster
Three different kinds of what look like roughly the same material. Would very much appreciate any definitive info

They are celluloid

[bleasure]

I've seen conflicting reports on these, but as I have several, I'd like to know for safekeeping's sake.

checkout this post here to determine if they are celluloid: https://www.allaboutpocketknives.com/kn ... hp?t=57923

They aren’t showing any signs of off-gassing so I’d rest easy but keep them on a regular inspection cycle.

celluloid*! too much time spent in between film prof and ecological prof. cellulose and celluloid get mixed up

[bleasure]

They are celluloid

can you expand on this - why do you think so, what is the proof? other celluloid syracuse scales, for instance, are pretty obvious. this material less so. especially given the range of difference across the different examples i have. is there a test i can perform that would chemically confirm things in an unambiguous way?

[bestgear]

is there a test i can perform that would chemically confirm things in an unambiguous way?

rub the knife covers on you pants leg until warm and smell them, if they smell like camphor then they are celluloid. Camphor smells bright, herbaceous, and with musty, earthy, and woodsy notes; the aroma of camphor is a cross between mothballs and vapor rub.

[orvet]

By looking at those knives, you can tell they are not mother of pearl. So you can rule out as a possible handle material.
The only other handle material that looks like that is kirnite, which is the rather recent invention within the last 20 years or so.
Those knives were most likely made in the 1950s or before. Celluloid was the only handle material in use at that time that looks like that.
Nu-pearl was a name Camillus used for celluloid made to look like MOP.

Hope this helps.

[edge213]

They are celluloid

can you expand on this - why do you think so, what is the proof? other celluloid syracuse scales, for instance, are pretty obvious. this material less so. especially given the range of difference across the different examples i have. is there a test i can perform that would chemically confirm things in an unambiguous way?

The age of the knives and the appearance of the handles material.

[bleasure]

thanks all. can't get any of it to smell any particular way, but i'm satisfied it's likeliest celluloid. it's too bad, i like all three quite a bit. celluloid is such a beautiful material, shame it literally caused buildings to explode and contributed to something like 80% of the silent era film stock's destruction

incidentally, black, jigged, plastic like covers on say, a syracuse knife - some kind of hardened rubber presumably? i have an old landers frary and cray with the same style of cover and they called theirs 'rubberoid' if i remember correctly. just trying to nail down who i have to be concerned about and who i don't.

[RalphAlsip]

I've seen conflicting reports on these, but as I have several, I'd like to know for safekeeping's sake.

49P no line Tuxedo
4-line Sword Brand coffin bolster

Three different kinds of what look like roughly the same material. Would very much appreciate any definitive info

I am not a chemist and won't be able to provide "definitive info". However, I am familiar with knife terminology and have observed the stability of knife handles over a period of years. The handles of the 2 knives without shields are often called cracked ice and sometimes imitation onyx by knife collectors. Whether they are created from a formulation of celluloid or a different formulation I do not know. However the scales from this material seem much less likely to offgas/outgas/deteriorate than the brightly colored celluloid handles.

In my antique knife collection, I stay away from synthetic handles including celluloid, cracked ice, pyremite, etc. In my modern collection, I do have a few micarta handled knives.

To show that rules still have exceptions, I do have the one cracked ice knife shown below. It is very rare and a pattern I happen to collect (Case 94). It is isolated from all my other knives.

[Mumbleypeg]

Beautiful example Jerry!

David is correct, they are celluloid.

When you have put in enough time collecting, handling, and examining pocket knives you will be able to identify celluloid on sight. At some point along the way you will have an epiphany - “that’s celluloid!” Like some other things in life, it is simultaneously beautiful, mysterious, unpredictable, and can break your heart. There’s nothing else like it but some modern acrylics can come close. (BTW just because it’s black doesn’t mean it’s not celluloid. It comes in infinite colors).

It’s sad that so many newer collectors have to rely on internet photos to see knives. The days of big knife shows having thousands of knives available to handle and ask about are sadly gone for the most part. If you’re into collecting and get a chance to go to one of the remaining shows, do it. And plan to spend several hours there. Which can greatly shorten the education process as versus looking at pictures on line.

Here are a few examples I have that are similar) to the OP knives (cracked ice, imitation pearl, imitation onyx, etc). They are all celluloid.

Ken

[bleasure]

Beautiful example Jerry!

David is correct, they are celluloid.

thanks! those are some neat examples. that case posted above is in great shape, what an unusual pattern.

i've been collecting for many years, dont let low post count fool you. as I mentioned, one part of my professional background is over 25 years in media and film, so am very familiar with celluloid both in terms of its history, and working with the material itself. i've archiverd and repaired hundreds of celluloid films in a wide array of decay states (vinegar syndrome). naturally knife covers are a different application, but i have enough experience to guide my instincts.

the problem i was running into, and the reason for the post, was conflicting information about 'cracked ice' specifically. regularly i have seen these covers called plastic and acrylic etc, in forums and on sale postings - enough, and in enough contexts to give me reasonable doubt about my first instinct (that it is celluloid). there were other plastics available in the prewar era, and besides metals, mop, wood, and bone, various synthetic substances (e.g. 'rubberoid' in my LF&C jackknife) were used as handle material, so this was at least plausible to me. as you point out, the opposite can also be true, and material at first glance appears to be rubber etc, may in fact be celluloid. the feedback here has been helpful in confirming my instincts.

[Mumbleypeg]

Thanks for that clarification. Your best indicator of whether it is acrylic is the age of the knife. To my knowledge acrylic has only been used for knife handle covers in the past 20 years or less. If the knife is older than that, it’s likely something else. There were a lot of other materials used, like hard rubber, gutta percha, fiberloid, etc. The list of possibilities is long. My recommendation, and what I practice myself, is if in doubt assume it is celluloid until proven otherwise. Then proceed accordingly.

Ken