Paleo preparation to make fossils look nice is usually the result of skill acquired with lots of practice working with fossils.  The basic techniques are fairly simple and are well described in various books or pamphlets on the subject, many of which can be read in public or school libraries. These techniques have changed little over a 
couple hundred years. They consist of scrapping off matrix, grinding off matrix, dissolving off matrix and stabilizing or strengthening weak fossil material. The tools to do this include hand-held scrappers, picks, hand-held grinders (I use a Dremel), air-abrasive units, water guns, acids for dissolving soluble matrix, etc.

Stabilizing is more specialized, but can be done with resins, which should be thinned before use. Another consideration is that in many situations, areas of the fossil already exposed during preparation should be protected from further attack by coating with a temporary protective layer. Usually, to do all this properly, you should be using a binocular microscope to check the fine detail as the work progresses. These are techniques that can be learned easily by some practice, and often practice is required to judge what will work with the type of rock and fossil you want to work on.

Teaching yourself with basic tools is really the best way to learn preparation.  Apart from the basic methods, three other factors are very important:
 

1) willingness to work slowly and carefully
2) evaluating the condition of the fossil, and
3) an understanding of what is possible in removing the matrix rock.

Careful and patient work is the hallmark of all good fossil preparation.  This includes an initial step of washing and cleaning the surface before doing further work, to better see the condition of fossil and matrix. In many cases, slow and even tedious work is the only way to do a good job of preparation. Do you want to spend a lot of time on a fossil?  The second factor is a critical step: deciding if preparation will really improve the fossil in hand.  This clearly requires some experience, which can be acquired by trying to do some preparation and accepting some
failures. Many, many fossils are not very well preserved and are suitable for garden rock, but not display material.  Preparation will not change that condition. Then, there is the matter of knowing the composition of the matrix and if, or how, it can be removed without destroying the fossils. For fossils like large bones and completely silicified shells, simple techniques may work well, but for a fossil very similar in composition or hardness to the matrix, grinding to remove matrix may be the only option. In this case, preparation may be impractical or will result in considerable damage to the fossil if not done in very small steps. This is especially true when using an air-abrasive unit. A water gun is better, if the matrix is moderately soft and the shell hard. If you have little experience doing preparation, a water gun is a better tool than an air-abrasive unit for softer matrix. If you want to remove hard limestone, a hand-held grinder with carbide bits (diamond if you can afford it, but these bits are
usually very small and too fragile) is the best tool. In all cases, clean the surface frequently and check to locate the precise boundary of the fossil. This equipment is not very expensive, except the binocular microscope and the air-abrasive unit.  The binocular microscope is the most important item for really good results, but you may not need it if the preparation can be done in a rough manner. 

By Thomas Yancey

(Thomas Yancey is a member of the "Rocks and Fossils" email list)

Tom, I agree with all you said... and might add one more thing. It is absolutely necessary to be as familiar as possible with the type of specimen you want to prep. I mean as to the size, shape, orientation in the matrix, number of appendages, etc.. If you know these things also, then prepping the specimen to present the way you want it to when finished is much easier. Try to cut the matrix to the size you want it before doing any work on the fossil, this way the specimen is protected from the effects of sawing, etc.. After sizing the matrix, for mudstones, I would recommend using grinders with diamond tips as Tom suggested to get the greater part of the matrix removed. Then begin the exposing of the specimen itself with scrapers of various shapes and sizes. Keep in mind, the round edge of a pick will remove matrix just as quickly as the sharp edge of a blade, and will not scar the specimen. I generally complete the prep with a quick airbrushing when warranted.

The following is a good place to get books... used, etc.., and they have been 100% successful with my needs over the past year:

http://dogbert.abebooks.com/abe/BookSearch
Good luck... C2
PaleoCarl@aol.com Carl J. Cook
SLIP St. Louis Institute for Paleontology
1704 Christine Drive
St. Charles, MO. 63303-4014 USA
636-949-2614
http://www.lakeneosho.org/SLIP.html

SOURCE:
paleo-quest   http://paleo-quest.skynetblogs.be/archive-week/2006-11

TYPES OF FAKE CHINESE FOSSILS

We have observed expertly done Chinese fossil fakes being sold on both Ebay and a few large fossil dealer websites.  Many of these CHINESE FAKE FOSSILS have sold for THOUSANDS OF DOLLARS with several selling for WELL OVER TEN THOUSAND DOLLARS!  Amazingly, many are being sold shortly after being listed! 

In a February 2000 issue of "New Scientist", an article focused on Chinese fossil fakery (New Scientist, "F is for fake," 19 February 2000).  Several highly respected paleontologists expressed extreme caution about the authenticity of Chinese fossils.  Most famous amongst them was internationally known paleontologist Dr. Larry Martin of the University of Kansas.  Perhaps his comment offers the most sobering warning to all fossil collectors and prospective buyers of Chinese fossils.  Dr. Martin stated "at the moment, I don't trust any of these specimens until I see the X rays!". 

The problem areas of Chinese fake fossils to watch for changes every year.  This list is not meant to be a comprehensive one but where we have seen some serious issues in the fossil trade.  Known areas of Chinese fossil fakes are listed below BUT ARE NOT LIMITED TO:

• ANY CHINESE FOSSIL SKELETON POSED ON MATRIX OR LOOSE, SHOULD BE HIGHLY SUSPECT!

• BIRD FOSSILS
• PTEROSAUR FOSSILS
• DINOSAUR SKELETONS AND SKULLS
• DINOSAUR CLAWS
• DINOSAUR EGGS
• MAMMAL SKELETONS AND SKULLS (Especially SABER CATS)
• KEICHOUSAURS AND OTHER AQUATIC REPTILES
• ICHTHYOSAURS
• FROG FOSSILS
• INSECT AND OTHER ARTHROPOD FOSSILS ON SLABS
• TURTLE FOSSILS
• CROCODILE FOSSILS

HOW THEY FAKE AND ENHANCE THE FOSSILS

The techniques are both ingenious and varied as to what the Chinese do to fabricate and substantially enhance fossils.  Most Chinese fossils are made by a combination of these processes.  These techniques include:

1) Using real materials (bones, teeth, body parts) to embed in glue, resin and plaster to create a complete fake fossil composite on a slab or piece of matrix.  (i.e. using modern chicken or frog bones glued to matrix to make various skeleton fossils).

2) Crushing genuine fossil bone and mixing with glue to fabricate body parts, skulls and skeletons that appear genuine with the proper color.

3) Casting, painting and sculpting a fossil on a slab or in three-dimension and even breaking it and then repairing it to appear genuine or give the appearance of calcite veins running through the fabrication.

4) Blending three-dimensional skulls (even using modern skulls!) of different animals together with artificially added real teeth to create fake skulls of rare, impressive animals. (especially a problem with Saber Cat skulls)  This has been done by adding genuine fossil teeth to modern skulls or attaching animal teeth to a composite of modern skulls such as pig, dog, horse, cat, etc. to create new exotic or rare species.

5) Assembling genuine fossils of unrelated specimens together to make a complete, impressive fossil.  The Chinese fossil fakers do this ALL THE TIME!  Even the dinosaur eggs are faked by creating a dummy egg-shaped core and gluing on a mosaic of unrelated fossil eggshell pieces that once were part of hundreds of different fossil eggs (sometimes you can still see the varying colors of the unrelated pieces!) together like assembling a picture puzzle, to make what looks like a complete egg!