Working metal by hand, pushing and refining its surface to create images that rise and fall with depth and detail, is an ancient craft that continues to captivate artists and artisans. Chasing and repoussé are two sides of the same coin, a partnership of techniques used for centuries to transform flat sheets of metal into intricate, three-dimensional artworks. Mastering these skills unlocks a vast potential for expression, allowing you to create everything from delicate jewelry patterns to robust architectural panels.
At its core, this process involves manipulating metal’s malleability. Think of it not as cutting or carving, but as sculpting the metal itself, stretching and compressing it to achieve the desired form. It demands patience, a good eye for form, and a sensitive touch with the tools. While the concepts are straightforward, achieving intricate detail requires dedicated practice and a deep understanding of how metal behaves under the hammer.
Understanding the Dynamic Duo: Repoussé and Chasing
Though often mentioned together, repoussé and chasing are distinct processes that work in tandem.
Repoussé: Pushing from Behind
Repoussé (from the French word for “pushed up”) is the technique of working on the reverse side (the back) of the metal sheet to create volume and raise the main forms of the design. Using specialized punches and a hammer, the artist carefully pushes the metal outwards. This is where the general shape and height of the relief are established. It’s about creating the hills and valleys, the broad strokes of the design, working from negative space on the back to create positive form on the front.
Chasing: Refining from the Front
Chasing (from the French word “châsser,” meaning to enclose or drive) involves working on the front surface of the metal. After the basic forms are raised using repoussé, the piece is turned over. Chasing tools are then used to define outlines, sharpen edges, add fine details, textures, and flatten background areas. Chasing refines the forms created by repoussé, adding the crispness and character that bring the relief to life. It’s the detailing phase – drawing the lines, adding the textures, smoothing the surfaces.
The beauty lies in the interplay. You’ll often switch between repoussé and chasing, turning the piece over multiple times, annealing it periodically to restore malleability. Each stage informs the next, gradually building complexity and refinement.
Gearing Up: Essential Tools and Materials
Having the right tools is crucial for success and control. While extensive collections can be built over time, a basic setup gets you started.
Hammers and Punches
The chasing hammer is distinct. It typically has a large, flat or slightly domed face for striking the punches and a smaller, rounded peen end, often used for texturing or planishing directly on the metal. The handle is usually slender and bulbous at the end, designed for a specific grip that allows for sensitivity and control rather than brute force.
Chasing punches (or tools) come in a myriad of shapes and sizes, each designed for a specific task. They are essentially steel rods with a shaped working end and a flat end for striking with the hammer. Key types include:
- Liners: Have thin, straight or curved ends for creating lines and defining edges.
- Planishers: Flat or slightly domed, used for smoothing surfaces and flattening backgrounds.
- Matting Tools: Feature textured ends to create stippled or patterned backgrounds, making the raised design stand out.
- Modelling/Raising Tools: Rounded or oval shapes used primarily in repoussé for pushing out broad areas of metal.
- Texturing Tools: Various shapes (dots, scales, grooves) for adding surface detail.
- Undercutting Tools: Used carefully to push metal slightly back under an edge, increasing the sense of depth.
These tools are rarely razor-sharp; they work by displacing metal, not cutting it. Keeping them polished and free of burrs prevents unwanted marks on your work.
Important Safety Note: Always wear safety glasses when performing chasing and repoussé. Metal fragments can occasionally chip off. Ensure your punches are properly heat-treated; poorly treated tools can shatter under hammer blows. Maintain a clean workspace free from clutter.
The Indispensable Pitch
To support the metal while allowing it to be pushed and formed, a yielding yet firm backing is required. This is traditionally chaser’s pitch. It’s typically a mixture of bitumen (asphaltum), plaster of Paris or brick dust (as filler), and tallow or oil (as a plasticizer). The exact recipe varies, affecting hardness and melting point.
The pitch is usually contained in a heavy, shallow container called a pitch bowl, often a cast iron sphere section resting on a leather or rubber ring, allowing it to be tilted easily. The metal is gently heated and pressed onto the warmed pitch surface. As the pitch cools, it holds the metal securely. To remove the piece, the pitch is gently warmed again.
Suitable Metals
The key property is malleability. Copper is an excellent starting point – relatively inexpensive, soft, and forgiving. Brass and bronze alloys are also commonly used. For finer work, sterling silver and fine silver are ideal due to their exceptional malleability. Even thin sheets of mild steel or aluminum can be worked, though they require more frequent annealing. Metal thickness (gauge) is also a factor; thinner gauges (e.g., 24-20 gauge or 0.5mm-0.8mm) are easier to move for beginners.
The Process: Bringing Metal to Life
Mastering chasing and repoussé is a journey involving several stages, often repeated.
1. Preparation and Design Transfer
First, ensure your metal is fully annealed (softened by heating and cooling). This makes it maximally malleable. Clean the metal surface thoroughly. Your design can be drawn directly onto the metal with a fine permanent marker or transferred using methods like carbon paper or decal paper.
2. The Repoussé Stage: Building Form
Gently warm the pitch until it’s pliable but not liquid. Warm your metal piece slightly (this helps adhesion and prevents thermal shock to the pitch). Press the metal, face down, onto the pitch surface, ensuring good contact. Let it cool completely.
Select appropriate raising punches. Starting from the center of the area you want to raise and working outwards, strike the punch with controlled blows from your chasing hammer. Move the punch systematically across the area, overlapping blows slightly. Don’t try to achieve full height in one pass! Work gradually, building up the form slowly. You are stretching the metal from behind. Focus on the major volumes first.
3. Annealing: Restoring Malleability
As you work the metal, it becomes work-hardened – brittle and resistant to further shaping. You’ll feel the resistance increase. Before the metal cracks, you must anneal it. Gently warm the pitch to release the metal piece. Clean off any pitch residue (a solvent like turpentine or mineral spirits might be needed, followed by soap and water). Heat the metal evenly to the appropriate annealing temperature (this varies by metal – often a dull red glow for copper/silver in low light), then quench or let air cool as appropriate for the specific metal. Pickle (acid bath) if necessary to remove oxides, then rinse and dry thoroughly.
Verified Practice: Frequent annealing is key to complex relief work. Ignoring work hardening is the primary cause of cracks and tears in the metal. Listen to your metal; when it feels stiff and sounds tinny under the hammer, it’s time to anneal. Don’t rush this crucial step.
4. The Chasing Stage: Defining Detail
After annealing and cleaning, warm the pitch again. This time, place the metal face up onto the pitch. Let it cool.
Now, select your chasing tools. Use liners to define the outlines raised during repoussé. Use planishers to smooth areas or flatten the background, making the raised design pop. Employ matting or texturing tools to add surface interest or differentiate areas. Work methodically, using controlled, rhythmic hammer taps. The angle of the punch greatly affects the mark made.
5. Iteration and Refinement
For detailed work, you will repeat steps 2-4 many times. You might perform some repoussé, anneal, do some chasing, anneal, go back to repoussé to push an area higher, anneal, chase again to refine the new form, and so on. Each cycle allows you to push the metal further and add more intricate detail. Undercutting tools can be used carefully at this stage to create deeper shadows and enhance the three-dimensional effect.
Achieving Mastery in Detail
Going from basic shapes to truly detailed relief is where artistry and skill converge.
- Tool Control: The angle you hold the punch, the weight of your hammer blow, and the rhythm of your strikes are paramount. Light, consistent taps are often more effective than heavy, erratic blows. Practice creating smooth lines, sharp corners, and varied textures.
- Sharp vs. Soft: Liners create sharp definition. Rounded modelling tools create softer transitions. Combining these allows for a full range of expression. Planishers, used carefully, can smooth repoussé marks or create deliberately faceted surfaces.
- Texture as Definition: Matting tools push down background areas, enhancing the relief. Different textures can represent different materials within the design (e.g., scales, fur, fabric folds). Texture isn’t just decoration; it’s part of the sculpting process.
- Depth Illusion: True deep relief requires significant metal stretching (and many annealing cycles). Careful use of undercutting can enhance perceived depth even in shallower relief by creating strong shadow lines.
- Pitch Management: The pitch’s temperature and consistency matter. Too hard, and the metal won’t move easily; too soft, and it won’t provide enough support, leading to mushy details. Adjusting the pitch recipe or working temperature might be needed depending on the ambient conditions and the work being done.
Finishing Touches
Once the chasing and repoussé work is complete, the piece needs finishing. This typically involves thorough cleaning to remove all pitch residue. Filing or sanding edges may be necessary. Depending on the desired look, the piece can be polished to a high shine, given a satin finish, or treated with patinas (chemical solutions) to create colours and contrasts that highlight the relief work dramatically.
Embarking on chasing and repoussé is to engage with metal in an intimate, transformative way. It requires dedication to learn the language of the tools and the behaviour of the metal. But the reward is the ability to create uniquely expressive, detailed relief work that carries the clear mark of the maker’s hand. Start simple, practice consistently, observe carefully, and the intricate beauty of chased and repousséd metal will be within your grasp.
