Using stencils to add to the range of decorative treatments is on the increase. They permit contractors to create intricate designs using mediums such as acid etch stain, sandblast or bead-blast profiling, tints and dyes, water-based stains, dust-on color hardeners, and colored overlay cement. Stencils can be constructed from a wide range of materials such as: wood, metal, paper, and plastic. Each has their special purpose. Steel, for example, could be the material of choice for doing repetitive sandblast or bead-blast patterning.
Stencils are a tool used by decorative contractors in the same way that stamps are a tool used for making an impression in fresh concrete. Contractors use them to create delicate patterns, logos, or simply as a mask to stop one treatment and start the next. Perhaps the fastest-growing stencil application is on diamond-polished concrete work where penetrating dye coloring is used to achieve translucent patterns that complement a floor, countertop, or piece of furniture.
Polyvinyl chloride (PVC) sheeting is the most popular stencil material. It’s available in a range of thickness, depending on the application requirement. It can be run through a plotter (a printer with a knife instead of ink cartridges) to cut patterns through the material. Most PVC also includes adhesive on one side, allowing you to stick it to the concrete surface so that it won’t move once in place—also providing a sealed edge between the concrete (providing the concrete surface isn’t too rough) and the edge of the stencil pattern so an application doesn’t bleed underneath. The strength of the adhesive bond also can be ordered depending on the substrate condition.
You can buy stencil material and create your own patterns, which some contractors do. A few adhere the material to a slab they are working on and then cut out the pattern. But most PVC stencils are created by businesses specializing in this type of work.
Two years ago, Rachel Bruce started Floormap Stencil Designs, Springdale, Ark., to design and cut stencils for contractors’ projects, occasionally working with owners directly on the creation of designs. She works with the contracting party and occasionally consults on projects to help ensure they proceed smoothly.
Any design is possible, even 3D ones. Bruce says most of her design work starts by using software programs such as Adobe Illustrator. In order for her to convert designs directly to stencil material, clients must send her information in a vector file format, such as an EPS, PDF, or Illustrator AI file. But some of her work comes as original artwork in the form of pictures and sketches, so she converts it to a vector file—a more labor intensive task. Occasionally she also is asked to create original designs for clients—work she particularly enjoys.
Doing multiple-layer stencil work
Bruce says the current trend is stencil on stencil work, also referred to as “layered stencils.” Clients increasingly want multicolored logos in their office entrance and demand is increasing for 3D graphics work. This is accomplished by building a design with several stencil layers, one after the other, on the same location. Each layer isolates different areas of the design, making it possible to add colors and effects along crisp lines—one section at a time. The process is possible through the use of registration marks that match up with each other so that each stencil can be precisely located in relation to the preceding one. Bruce says she previously worked in the printing industry, where using registration marks have a long history.
There are many ways to register the location of one stencil with succeeding stencils. Bruce’s system involves cutting out square holes at the same location for all stencils in a multiple stencil system. The first stencil layer includes the registration squares that are cut into the vinyl panel, but not removed. These stick to the concrete and remain in place until after the final stencil layer is applied and removed. All the other stencils in the system only have a square opening in them so they can fit over the square left by the first stencil. By doing this, each new application of color is precisely located in relation to previous color placement. Bruce says the more registration marks included on the stencils, the more accurate the lineup will be.
The 3D effect sought after today is closely related to the different colors included in a graphic—colors which come together at crisp intersections, especially when applied with airbrush spray guns in the hands of creative artists. The best way to achieve this is through the use of multiple stencil layers. Bruce says the most she has included in a single graphic so far is seven layers.
Working with stencils
Carlos Perez, owner of Custom Concrete Specialists, Lakeworth, Fla., does a lot of stencil work on polished concrete. He says he frequently works with multistencil layers to provide 3D effects for his customers. “It’s great to make people look at the floors instead of the walls in a building,” he says.
Perez recommends diamond grinding a floor to a 200-grit finish before starting stencil work. “You need enough porosity for stains to penetrate but smooth enough concrete so that stains don’t bleed beneath the stencil.” He further cautions that you have to be a little careful when you place PVC stencils so that they don’t stretch out of shape too much, forcing decisions about how to get a best fit when registration marks don’t quite match up. He adds that sometimes openings in succeeding layers pass over preceding colors, allowing for the creation of shadows. When doing this, he suggests applying darker colors first, following up with lighter colors.