Cleaning
Use a soft, all-cotton cloth or chamois to clean your knives. Then apply a coat of Simichrome Polish and wipe it off A protective film will remain on the entire knife. A number of collectors are using a wax called “Renaissance.” It has very little grit and does not leave any white film around edges and cracks. Never use Vaseline because it allows moisture to seep beneath its coat and cause rust. It is a good idea to check your knives often for possible trouble spots. 

Caring for Your Knives
Rust is as old as iron, and finding a cure for rust is like finding a cure for the common cold. Some precautions should be taken so your collection of knives will not diminish in value.

Storage and Handling
The most recommended method of storing knives is in vinyl rolls with a cloth interior. The rolls also provide a convenient way to transport knives. Leather rolls have a small amount of tanning acid in them, which can cause rust. If possible, leave your knives unrolled during storage; this allows air movement and reduces moisture.
Display cases with felt interiors are another way to store knives and also allow a collection to be exhibited easily. Some collectors use elastic bands to attach their knives to the display, while others use wire. Elastic makes it easier to slip knives in and out for closer inspection, while wires must be cut and replaced each time.
A Plexiglas top will also cut down on dust and possible theft.
Transporting your knives from cold to warmth will cause condensation, resulting in rust. In other words, don’t leave your collection in your car trunk overnight during cold weather and then bring it into a show the next day without expecting some condensation. Keep your knives at a constant temperature or at least within a few degrees at all times.
Caution:
Celluloid is made from a petroleum base and emits fumes. The fumes will cause rust, so keep celluloid knives stored separately.
Direct sunlight can fade almost anything. Knife handles are fragile, especially bone, stag, and pearl, so don’t toss them around carelessly, and don’t drop them. Broken or cracked handles reduce value.

What to Collect:
Some people collect everything, as long as it is of excellent quality and brand. Then there are other schools of thought such as collecting within the following categories:
Patterns: trappers, peanuts, gunstocks, etc.
Handle Materials: goldstone, pearl, Rogers bone, etc.
Manufacturers: Case, Queen, Schrade-Walden, etc.
Specialties: advertising knives
Beginners should make a decision before investing a
lot of money in a collection.

Knife Condition
Mint: Never been carried or sharpened, straight from the factory and sometimes in the original box.
Excellent: Handles are in good shape, blades still close with a snap and show only slight wear.
Very Good: Blades show approximately 25 percent wear and handles are in good condition; although one blade may snap weakly, blades have not been repaired or changed, and stamp can still be seen clearly with the naked eye.
Fair: Blades show 50 percent wear, blade closing is mushy, handles are cracked or replaced, blades are repaired or changed, stamp is weak.
Poor: These are used mostly as parts knives and have well worn or broken blades, handles are broken or completely missing, stamp is barely visible, if at all.

Counterfeiting

Counterfeit: “Something made to imitate another thing with the intent to defraud.”
In 1999, Gerald Witcher made an enormous contribution to knife collecting by publishing a book about counterfeiting We highly recommend you purchase this masterpiece from the NKCA or from Knife World. As prices increase, the darker side of human nature emerges. Unscrupulous people alter less valuable knives to look like genuine rare ones. Why not add two dots and make an 8 dot 6488 into a 10 dot 6488? Why not shave off the tang stamp of a USA knife and make it a XX knife? For that matter, why not shave off a XX tang stamp and make it a Tested knife?
The only safeguard for the collector is knowledge. Witcher displays various examples of genuine and fake items: a good stamp next to a bad stamp, a good blade versus a bad blade, a good frame versus a bad frame, a good shield versus a bad shield, good handles versus bad handles, and the list goes on and on. This is not a sit down and read it in one night type of book. This is something that will become your bible.
He explains the history of companies through tang stamps. He also provides individual knife critiques for the following manufacturers: Case, Eagle, Eye Brand, John Primble, KA-BAR, Napanoch, New York Knife, Queen, Remington, Winchester, Shapleigh Hardware, Russell, and Bowie.
If you deal in knives that cost more than $100, this book is one of the best investments you can make.