With a source book containing over 500 references, it is never easy to select the right Gravotech engraving material for you and your customer. With over 80 years of expertise in engraving, this guide will help you identify step by step the different criteria to take into account when choosing an engraving material for signage projects.

What Is an Engraving Material?

Gravotech has been developing its own plastic engraving materials for over 50 years. A plastic engraving material is an assembly of several layers of plastic in different colours. The principle is the same for laser marking or mechanical engraving: by removing part of the upper layer, the lower layer is revealed and another colour appears to obtain a contrasting engraving. Text, drawings, logos, and pictograms can all be engraved.

Layer Configurations

To meet all application needs, Gravotech offers materials with different types of assembly:

Technical Variations

The bottom layer is called the core and the top layer the surface. By varying their thickness, it is possible to obtain different engraving and cutting results:

Core Composition

The core composition is selected to provide specific properties. PMMA cores are the most popular -- they are versatile, long-lasting, and resistant to harsh environments (bad weather, industrial conditions). They can be processed by laser or rotary engraving. ABS cores are more economical and bring a certain flexibility to the material. They are intended for indoor use and are generally processed by rotary engravers, as ABS is not suitable for laser cutting.

Criteria 1: The Machine Technology Available to You

The first criteria to consider when choosing a material for engraving is the technology of your machine -- mechanical (rotary) or laser, or both. Not all materials can be engraved or cut with both technologies.

Mechanical Technology

If you have a mechanical engraving machine, almost all Gravotech engraving materials can be used for both engraving and cutting. It is important to note that some materials, such as wood, acrylic, or brass, will not naturally produce contrasting engraving. If you wish to add contrast, you can use a colouring product after engraving.

Laser Technology

CO2 lasers generally produce a naturally contrasting engraving without any additional product. Some materials, such as wood or acrylic, can be engraved with both laser and mechanical machines. However, some material ranges, such as ABS-based plastics or metals, can be engraved with a laser but not cut. In this case, you can use Gravotech's cutting service -- order materials already cut to the desired dimensions, and simply carry out the engraving. Important: PVC materials should be avoided altogether for laser engraving, as PVC releases harmful substances such as chlorine under the effect of the laser.

Material Compatibility by Technology

For rotary engraving indoors, compatible material types include: plastics (Gravoply 1, Gravoply 2, Gravoglas 2-Plex, Gravoply 3C, Ecocut), acrylics, flexible sheets (Flexilase, Gravofoil), metallics (Metallex, Gravometall), metals (Gravobrass Exterior, Colored Aluminum, Gravoxal), phenolics (Gravostral, Gravostrat), and accessibility signage materials (Gravotac).

For CO2 laser indoors, compatible materials include: plastics (Gravoply Laser, Gravoply Ultra, Gravoply 2), acrylics (Gravoglas 1, Acrylic, Ecocut Laser), flexible sheets (Flexilase, Rubbalase, Stickalase), metallics (Gravolase Metallics, Colored Aluminum), metals (Gravoxal, AlumaMark, DuraBlack), phenolics (Gravostrat), accessibility signage (Gravotac Exterior), and wood (Laser Wood).

Criteria 2: The Environment of Your Signage Projects

Outdoor Applications

For the harshest exterior applications, the "Material + Engraving" combination is by far the best because it meets durability requirements that no other technology (such as UV printing) will achieve. Outdoor signs are subject to much greater stress than indoor ones. The materials must:

From a technical point of view, PMMA (acrylic) type materials are considered suitable for outdoor environments. ABS-based plastics or wood are not suitable and will degrade more rapidly. If the environment is very restrictive, use thick materials and engrave them deeply. Materials like Gravoglas 1 are engraved on the back and protected from the outside elements by a transparent acrylic face, resulting in extremely durable signage.

Indoor Applications

For indoor applications, the choice of materials is generally wider with fewer constraints. However, certain industrial environments require signage that can withstand chemicals or extreme temperatures. Some indoor applications can be considered as outdoor -- for example, a nameplate placed near a window must withstand UV exposure. The same applies to nameplates in engine compartments of vehicles or in sheltered but unenclosed environments like station platforms.

Criteria 3: The Composition and Aesthetic Rendering

Type of Material

Usually manufactured in two-layer format, some Gravotech materials are designed in single-layer, three-layer, or even double-sided versions. They may vary according to:

Surface Finish

Each material can be offered with different finishes: plastics are often matte, but can also come in satin, glossy, or even brushed. Metals and plastics with a metallic effect are generally glossy or brushed. In a brightly lit room or outdoor environment exposed to sunlight, the natural shine of metals can impair legibility -- in which case matte materials, often plastics, should be used instead.

The Choice of Colours

The desired appearance is important in your choice of material. Should the engraved characters be contrasting or tone-on-tone, plain colour or metallic? For high-end, traditional signage, metals and metallized plastics always work. For colourful signage to meet a graphic charter or a standard, plastic materials offer the greatest possibility of diverse colours.

Thickness Considerations

Technical constraints may require a specific material thickness. The most popular thicknesses for two-layer materials such as Gravoply are 1/16" to 1/8", offering a good compromise between rigidity, cost, and durability. Gravotech generally offers several thicknesses in each engraving material range.

Budget

Customer expectations must always be set against their budget. Metals are particularly high-end when it comes to engraving but are much more expensive than plastics. Metallic-effect plastics are a real alternative for even the tightest budgets. Most materials are available on request with an adhesive backing for direct attachment to smooth or rough walls. Flexible materials such as Flexilase can even be bonded to rounded surfaces.

Rendering Example

For metallic nameplates, Gravobrass Exterior is often the material of choice for a high-end image. But alternatives exist with interesting characteristics: Gravoglas 2-Plex Subsurface is an acrylic (plastic) material that is non-oxidizable and cleans more easily than brass, available in high-end metallic effect colours at a more attractive price. Gravostral is a phenolic-based hybrid material with a brushed aluminium surface -- while not suitable for outdoor use, its two-layer (two different colours) design means it does not require a colouring product to achieve contrast.

Criteria 4: The Type of Information on the Signage

Signage meets a variety of needs: guiding and orienting people, identifying and signalling spaces or objects for information or regulatory purposes. These objectives also influence the choice of materials.

Informative or Directional Nameplates

This category includes a vast set of indicative plates, sometimes normative, which can be personalized to the charter of a company or a place. Examples include badges, trophy plates, directories, location maps, small labels, and small flexible labelling. These can be used both indoors and outdoors. The dimensions to be covered must be taken into account -- at Gravotech, the maximum size for a sheet of raw material is 24" x 48", although exceptions exist.

Signage in Industrial or Normative Environments

In industry, signage must very often comply with specific specifications and constraints. There are three types of industrial signage:

Several of Gravotech's material ranges have specific technical characteristics designed to meet these requirements. The colours offered in some ranges meet colour codes established in numerous international standards. For industrial or safety signage, materials like the Gravoply 3C range are specially designed for these applications.

Accessibility Signage

Accessibility signage for shops, government offices, and public places enables many people to get around and find their way independently. Standards concerning the accessibility of public places to the visually impaired are important. The Gravotac and Gravotac Exterior ranges have been developed to meet visual contrast standards and are compatible with Braille beads for tactile signage.

Conclusion

Now you know the key criteria for choosing your engraving material: your machine's technology, where the sign will be mounted, the aesthetics your customer expects, and the type of information the sign will carry. With all these criteria in mind, your choice of engraving material will become more defined. Gravotech's comprehensive range of over 500 material references, combined with expert guidance from SOFRAY EMS, will help you identify the range of materials that meets all your expectations.