Coin Designers - Tony Dean Part 2

November 22, 2009

We spoke about our visit to medal and coin designer Tony Dean's studio in part 1 of our article about coin designer Tony Dean. In this second part we'll speak about the process that he goes through when designing and manufacturing a new medal.

Initial 2 Dimensional Designs and Sketches

The initial part of the design process is done via sketching or computer aided graphic design. Tony will either hand draw or mock-up various designs using 2d computer software such as Photoshop or Illustrator. This enables him to produce a number of different design alternatives quickly that can be approved or rejected by his clients. They are also easily modified as design improvements and tweaks are trialed and accepted or rejected. Obviously working in 2 dimensions doesn't allow for a true impression of the beauty of a 3 dimensional design but it is much quicker and cheaper method in initial stages of the coin or medal design.

Plaster Model (left), Silicone Mould (right)

Making the Plaster

Once a medal design has been approved in 2 dimensions work begins on sculpting a large model of the medal. The model is made from high grade dental plaster discs that appear to be 8 to 10 times bigger than the final medal size. Three dimensional elements of the design are built up in plasticine on a sheet of glass and a disc of plaster is cast against this model and glass surface to produce a negative image.

Tony can then speed up the sculpting process by making use of a pantograph reducing machine to carve more simple features such as medal rims and lettering in to the plaster model. To do this Tony prints out the features to be added and etches them into a copper template using copper etchants. This template can then be used in the pantograph reducing machine to machine an exact copy (enlarged or reduced as required) of the design into the plaster model. If you're wondering what a pantograph is try taking a look at this what is a pantograph article on Wikipedia. Tony's pantograph has a small motorised machining head on one side to carve out the design features into the plaster. You can see a picture of his machine below.


Tony can go through multiple plaster models to get the design just right. For example it may be easier to sculpt and refine some design elements working on a negative image model, while others may be easier to refine on a positive image model. When he needs to create a new plaster he coats the old one with a separating agent and casts a new disc from dental plaster against it producing a reverse of the model he started with. The very fine nature and high quality of the plaster means no detail is lost by casting new models. Tony takes 1-3 weeks to produce the plasters for a medal. Remember he has to produce a positive plaster for each side of each medal or coin that he designs so the process does take some time. To be honest when we saw the level of detail he puts into the plaster models 1-3 weeks to produce two plasters seemed awfully quick!

Making the Dies

Once the plasters are complete a silicone cast is made from each plaster (you can see one of these silicones in the first image on this page). The silicone mould is used to cast (there certainly is a lot of casting going on!) a hard epoxy resin positive image of each side of the medal or coin. The epoxy resin model is then used in what is known as a 'reducing machine'. A reducing machine is a special machine used in the engraving and coin making industry to accurately reduce and machine a coin or medal design into tool steel. Put simply the machine uses the hard epoxy model as a guide to reduce and engrave the design into steel. The machine will often run for several days and may make several passes over the design using progressively smaller tool heads to refine the design. The design that has been copied into the steel is known as the hob or reduction punch, you can see a hob on the left below.

Hob (left), Die (right)

The hob is inspected closely (under a microscope) for flaws and any last minute modifications made to it using specialised hand tools. It's at this point that any special treatments are made to the design (such as frosting or polishing). Once the hob is accepted it is heat treated and annealed to increase the hardness of the hob. The hob is then pressed (using a hydraulic press) into more tool steel to form a negative image of the design. This process (known as hobbing) may require several steps before the full detail of the design is pressed properly. The steel being pressed may need to be removed and heat treated to remove the effects of work hardening so the design can be achieved properly. For the error collectors among us mis-alignment of the two work peices during multiple hobbing steps can lead to 'doubling' known as hub doubling.

Finished Medals

Once the design is pressed in satisfactorily we have what is known as a die. Please note that in the coin manufacturing process there's a couple of extra steps in here (to create working hobs and production dies). In Tony's low volume medal manufacturing process, however, the die created from the first hobbing process is used to make the medals. The obverse and reverse dies are installed into a coining press and medal blanks (Tony has minted medals from copper, bronze, silver and gold) are struck to produce the medal. Any post production finishes are then applied to the medals (such as antiquing, electroplating and so on). It is also at this stage that other components may be added to the medal such as ribbon hangers. Above you can see two finished versions of the same medal.

Hand Cut Hob

Hand Cut Hobs

As mentioned in the first part of this article Tony learned his art under the tutelage of Emil Hafner. While there Tony would actually engrave the hobs directly rather than working in plaster. This required the use of special engraving tools, a microscope, and mind boggling skill and care. Obviously tool steel is much harder to work in that plaster, and one mistake could mean starting from scratch! Above you can see one of the hand cut hobs that Tony has created.

In conclusion we'd like to thank Tony for allowing us to visit him at his company's premises and for taking up so much of his time. Tony was very forthcoming and open about his experience and the design process that he goes through. We were certainly amazed at his skill and the beauty of some of his designs and found everything to be extremely interesting. If you're in the market for a medal or plaque he's happy to work with anyone in Australia and working remotely with customers seems to pose no challenge to him. His company has access to all the equipment required to see the medal making process through from concept to striking and delivery of the final product. With Tony designing the medals you have access to a truly world class designer, after all it's not often you can get access to the skills of someone who designed a number of Australian $1 coins! Don't forget to go take a look at his web site: Medal Art Mint.

Posted by mnemtsas at November 22, 2009 7:17 AM
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