This is a general information article about the various methods of engraving stone granite and marble etc.
There are several methods of engraving natural stone, the ones most commonly used are “Etching”, “Machine Cut”, “Hand Cut” and the method we use “Deep Cut Engraving”. This is a brief explanation of the choices commonly available.
(NB: When we refer to stone it includes any type of natural stone, slate, granite and marble).
DEEP CUT ENGRAVING:
The lettering is deep cut into the solid stone using grit blasting, commonly referred to as sand blasting. A more accurate description would be “Sand Carving” as the process is far more skilled and subtle than it first appears.
This method requires very high pressure equipment, careful preparation and a lot of time!
The size and spacing of the lettering is completely flexible, and the quality and variety of the artwork is only limited by the ability of the company artist.
The lettering and any art work can be very cut deeply into the stone, this means the lettering and any art work “stands out” – it has depth, shape and shadow. So much so that 75% of our signs go out unpainted and are perfectly legible. They also have a very long life. These signs will still be readable after decades of weathering.
Etching has been around in various forms for a long time, most people will be familiar with pictures printed using etched copper plates.
The image is either scratched or burned into the surface of the copper with acid.
Stone, slate and granite are of course much harder than copper but the principle is the same. The image is lightly scratched onto the surface of the stone with an engraving machine or very light blasting or is burnt onto the stone with a laser cutter. This creates a thin but permanent shadow image on the surface of the stone. On some materials such as black granite the image can be quite clear and readable, the problem is that when the stone gets wet the image becomes all but invisible. Therefore, stone etchers rely on coloured fill, paint or stain to highlight the image or letters.
The useful life of the sign depends entirely on the ability of the coloured fill to withstand weathering.
The advantages of etching are that it is possible to produce highly ornate artwork or very small text and the manufacturing process is relatively flexible.
Machine cut slate house signs are very common. You can spot them because unlike blasted or etched signs the letters are v-cut and the serifs of the letters tend to be rather heavy and rounded, unlike hand carved or deep cut lettering where the serifs are sharp.
The letters are cut using a large pantograph type machine. It is unusual to see machine engravers working on the harder stones such as Indian sandstone or granite as these types of stone are too hard for the cutting bits. The engraving using this method is deep and will still be readable when the paint has weathered away.
The disadvantage of this method is its lack of design flexibility.
The type of font and the size and spacing of the lettering depends entirely on the available jigs. This is why most of these signs are priced per letter, longer names need longer pieces of slate or stone. Also the artwork and lay-out options available will be very limited.
Letter-cutters are a rare breed nowadays. When I was an apprentice back in the 1960’s (cue sad plaintiff music!) most headstones were still lettered by hand, using hammer and chisel, and tradesmen letter cutters were considered to be (forgive the pun), a cut above us masons.
The lettering was drawn onto the face of the stone in pencil, the lay out and spacing was done largely by eye! Then each letter was individually carved with hammer and chisel. Some letters were v-cut and painted but the majority of the work was for lead filled lettering.
The process is still the same today, the main change is that most hand letter-cutters today have come to the trade via the artists route, learning to draft the designs and fonts at art school rather than in the more disciplined arena of a masons workshop. The designs and fonts tend to be more artistic and free flowing, each piece of work the product of inspiration and skill. Thus modern hand cut inscriptions are considered to be works of art, rather than mundane products of craft.
Today finding a letter-cutter is a problem and of course a hand cut house sign will (rightly) be very expensive. However if the engraved stone is important enough and you can afford the extra cost it may be well worth it!