1 May 2024

Sandblasting offers opportunity into numerous markets. From extremely fine detail to personalized characterization to multi-level deep carving, the possibilities with sandblasting are virtually limitless. Today, the easiest way to carve is commonly referred to as sandblasting; and photoresist film makes it even easier. 

What is Photoresist Film?

Photoresist film is a material used in an exposure and development process to transfer tremendous detail for decorative sandblasting applications. When exposed to UV (ultra violet) light, the film undergoes cross linking in its chemical makeup to increase or decrease resistance to abrasive. Combined with a photo positive artwork image to block light where desired, the film becomes a precise stencil of any artwork and can be applied to many different substrates. After application to a substrate the piece can then be sandcarved leaving a permanent design on the substrate. 

Benefits of Using Photoresist Film over Other Methods

Photoresist films are the leading technology in the sandblasting industry. They provide multiple benefits over alternate methods such as plotter cut vinyl, chemical etching, and laser engraving. The three primary benefits of photoresist films are its retention of fine details, ease of use, and the variety of substrates to which they can be used. 

When using photoresist film, very fine detailed designs can be achieved that are unattainable with other methods. It can transfer any image, including halftone photographs from your computer onto the resist. This amount of detail is not possible with plotter cut vinyl or acid etching. Additionally photoresist films are much easier to use, eliminating error and loss of time. 

Traditional hand cut vinyl is labor intensive and plotter cut vinyl requires the user to manually weed out or pick out the images before sandcarving. Photoresist films use water and light to develop details the human hand is incapable of resolving. Lastly, although modern innovations such as laser engraving allow for automated processing of the film, lasers are limited to flat substrates, light surface etches, and a rough chipped finish rather than the smooth lines sand caving provides. While lasers do work well with wood and plastic, they are not ideal for glass and curved surfaces.

The overall benefits of sandcarving are easily seen when using brittle substrates where both very fine detail and deep carving can be achieved. The combination of deep carving, fine detail, versatility of substrates and ability to acid color to sand­carved pieces lends itself to creating high value pieces. As an example, some markets can see 70% to 90% gross profit margins. 

Purpose Of Different Film Thicknesses

Photoresist films vary in development process, thickness, and adhesion depending on the need of the project. Each of these variables allow users to compete in diverse markets. Photoresist film comes in a range of thicknesses from 2mil to 10mil thickness. The thinner photoresist will hold much finer detail, including halftone photo images, and the thicker photoresists allow for increased depth. 

For example: with a 10 mil film applied on glass users can sandblast over an inch deep. When used on harder substrates like black granite, a 10 mil thick photoresist will achieve from ¼ to ½ inch depth.

The variety of thickness and designs allow users to access many types of markets using photoresist film and sandcarving. The primary markets using photoresist are awards and engraving, architectural, monument, signage, donor recognition, promotional, and the wedding industry. 

Dry Process vs Wet Process Photoresist Film

The process to develop photoresist films is very simple and contains just one or two steps. Over thirty years ago photoresist sandcarving started using water to develop exposed films. Similar to screen printing, the wet process utilizes a photopositive for the art tool. The photopositive is transferred to the resist via UV exposure and water development. During the water development (also known as the wash out stage) the film is sprayed with warm pressurized water until the stencil is revealed. After wash out the photo resist is dried and then applied to the substrate and the piece is ready to blast.

With the dry process, customers use a photo negative for their art tool. The photo negative is transferred to the resist through UV exposure. After exposure the resist is ready to be applied to the substrate and is ready to sandblast, therefore eliminating the wash out and drying steps. 

With both the dry and wet process photoresist stencil material, you can carve on flat and curved substrates. Brittle materials such as glass, crystal, stone, ceramic, marble, granite, and wood are perfect substrates for sandblasting deep carved designs. Metal, plastic, acrylic, and any other less brittle materials are ideal for surface etching rather than a deep carve. 

In conclusion, from the finest of details etched in glass, to deep carvings into stone monuments, photosensitive films are versatile, easy to use, materials that can create high end designs in all types of markets and substrates. Together the innovations in photoresist films and sandcarving cabinets have modernized the art of sandblasting and have brought it to the forefront of many new markets where potential and applications will only continue to grow.