Silk-screening ceramic frit onto glass lets a designer create a subtle or bold look for a building-using patterns and color. Silk-screened glass improves solar control performance and can be combined with clear or tinted glass substrates, as well as with high-performance coatings to reduce glare and decrease solar transmission.
The first step in silk-screening involves washing the annealed glass. Then, the ceramic frit paint is applied to one side of the glass. Next, it is fired within a tempering furnace to create a permanent coating. The glass is always either heat strengthened or fully tempered to prevent glass breakage due to thermal stresses under sunlit applications.
When designing with silk-screen patterns, it is important to select the pattern (screen), select the color for the pattern and identify the pattern orientation.
Viracon offers a variety of standard Viraspan™ Design patterns as well as the ability to customize a façade using your own Viraspan Design – Original .
Viraspan Design - Original
Borders, graduations or custom patterns you design.
Viraspan™ Color Options
Viracon uses only lead free ceramic frit paints, which are environmentally friendly, to apply the silk-screen pattern onto the glass surface. A proven performer, Viraspan ceramic frit paints are the product of choice for color consistency, durability, cost control and long life. For silk-screen applications, Viracon offers translucent and opaque (when viewed in reflection with an opaque uniform background) ceramic frit color options.
Pattern placement, aka orientation, must also be considered when specifying silk-screened glass and should be included in the drawings if you are using a line pattern or for all other patterns if a specific orientation is required.
Viracon recommends applying the silk-screen pattern to the second (#2) surface for optimum solar performance. The Low-E or reflective coating can be applied to the same surface as the silk-screen pattern.
Specifying Silk-Screened Glass
When specifying silk-screened glass, include the pattern, color and orientation in the overall glass composition. If it is not practical to describe the orientation in the specification, a drawing should be referenced to clearly identify orientation.
Silk-screen Design Guidelines
Silk-screen patterns may be applied to any surface except the exterior (#1) surface. Viracon recommends applying the silk-screen pattern to the #2 surface for optimal performance. See silk-screen performance for additional information.
1/16” minimum dot, pixel or space
For coverage options, refer to ceramic frit coverage rules below
Dual Surface Patterns
Placing a silk-screen pattern on two surfaces within an insulating unit is feasible however extreme caution should be taken during the design process to minimize the potential for a moiré pattern to appear. Recommendations for designing dual surface patterns can be found in our Ceramic Frit and Ink Visual Characteristics Tech Talk.
Ceramic Frit Coverage Rules
All maximums listed are for any one square foot area of a glass unit.
**Not available for interior applications and not available with coatings on the same surface. Also, when translucent frit is used as full coverage, inherent characteristics may make this product unsuitable for vision areas. These characteristics include slight variations in color and uniformity, pinholes or streaks.
When considering translucent frits for spandrel applications note that these areas may be prone to condensation formation on interior glass surfaces. Over time, this may result in a visible film formation. Therefore, consideration must be given to the suitability of these products in spandrel applications. For these applications, the translucent frit may only be applied to non-exposed surfaces. See silk-screen inspection guidelines and manufacturing tolerances in the quality section for additional information.
Moiré is an optical phenomenon that typically appears as a wavy, rippled or circular pattern. It is formed when two regularly spaced, non-aligned patterns overlap. Moiré is not a defect in the glass, silk-screen or digital printing process but rather a pattern formed by the eye. For additional information, please review Viracon’s Ceramic Frit and Ink Visual Characteristics Tech Talk.