Encaustic has been gaining in popularity among artists and collectors since Jasper Johns re-imagined the medium with his famous flag paintings. But the methods and materials had been perfected much earlier. Phoenician ships were both decorated and waterproofed with encaustic decoration, and portraits on wood and funerary masks from Greece, Egypt, and the Mediterranean basin still hold their vibrant colours and luminous surfaces.
Repair and restoration of encaustic artworks benefits from the fact that the encaustic medium is unchanged: a mix of dammar resin and filtered beeswax, the mixture can be reapplied to an artwork for preservation without changing the work. But the encaustic medium is only one part of the artwork, and problems have cropped up for collectors and curators attempting repair and restoration.
The weight and mass of encaustic artwork demands a structure that can support the heavy weight. But even hardwood panels can crack over time if not properly prepared and supported. Cracking in a wooden support can be minimised by adding a new wooden backing material. Any encaustic works on textile or canvas have a shorted lifespan, but conservationists can re-back them with wooden support panels and retain the original textile support.
Inclusions and collage materials chosen by the artist may or may not have been acid free and of archival quality materials. If materials included in the artwork, such as old newspapers and letters, have begun to change or deteriorate due to acid in the materials, reapplying encaustic medium to the surface and making sure the structural backing is intact can reduce the exposure to the pieces to the environment. But it may be in the nature of a particular piece for the changing condition of inclusions to be part of the artwork. If original inclusions are removed and replaced, the value of the artwork is impacted.
The surface of encaustic is unique, and the luminosity, light, and depth of the surface is what draws collectors and curators to the form. The wax can bloom a cloudiness for the first six months, and depending on the thickness of the application, some smaller cloudiness can be observed for up to three years. Gently buffing of the surface in a circular pattern with a soft cotton cloth, such as an old diaper, removes the surface cloudiness in the early life of the artwork. The surface is also cleaned the same way if dust is noted.
Encaustic is an organic surface material. It will react to the environment, but should never be covered with glass. Extremes of temperature should be avoided, as well as direct sunlight on the surface of the piece. But no other protection should be given that will reduce the exposure of the art to the environment; that could precipitate increased humidity, mould, and sloughing of the surface. Encaustics should be buffed on occasion, their wooden supports inspected for cracking, and otherwise their unique surfaces and colours should be enjoyed without barriers between viewer and artwork.