Safety Statement

The chemicals used to produce Wissmach Glass products are in a glass matrix. These chemicals are not available to the environment unless the glass is heated to its melting point or ground to an extremely fine particle size. Many art and kiln glass products are made with metal oxides. While those metals are bound in a glass matrix, grinding the glass to an extremely fine mesh size can liberate some of the metals in the glass. Your glass retailer or supplier can recommend tools and preventative measures for personal safety while working with art and/or glass products.

The State of California requires clear and reasonable warnings on products containing chemicals that have been shown to cause cancer, birth defects, or other reproductive harm, even if the products contain only trace levels.

Manufacturers of certain products, like Wissmach Glass, include warnings pursuant to California Proposition 65. Caution is recommended when using products marked with the Prop 65 icon.

Art Glass Considerations

Every effort has been made to accurately reproduce the glass colors of the images on this website. However, some colors are more difficult to photograph than others. We encourage you to refer to your Wissmach sample set when an exact match is needed for your project.

The glass images shown in our Art Glass Catalog represent only a small selection of our entire glass line. Please let us know if you want an actual glass sample for any of the missing images.

Art Glass is non-fusible glass sheet. These items are intended for stained glass, mosaics, and other cold working applications. They are not intended to be kilnformed/fused.

Color tolerance: color will be one-half shade lighter or darker per 1/8” thickness.

DO NOT glaze excessively large lites. All colored glass is subject to thermal shock caused by solar heat that the glass absorbs.

We do not recommend glazing colored, rolled-sheet glass in precast concrete openings, metal beads (screw-in or snap-in type beads) or spring clips with too much tension.

A space of 3/16″ should be between the glass and the rabbet. The glazing media should be one that will stay pliable.

We do not recommend glazing individual lites over 2.5 square feet per lite. We suggest keeping the size limit well under the mentioned size in all thicknesses of glass.

Wissmach glass is a handmade product. All colored glass is subject to inherent warpage, tiny bubbles, seeds, and surface scratches. These properties in no way affect the glazing quality of the glass.

Mixed opalescent glass will vary in color mixture and density in each sheet as the glass is mixed by hand.

COE 96 Kilnforming Considerations

There is no “one-size-fits-all” firing schedule for kilnformed glass. Even two kilns of the same manufacturer and model can give your projects different results. Kiln glass is an exciting and fun art form, and we have compiled some tips to ensure that your projects achieve the best results possible!

We recommend performing small tests with your glass when using a new firing schedule before embarking on larger projects. This practice will help you better understand how your kiln performs with Wissmach glass.

Maintain a notebook where you can keep firing schedules along with notes and results to build a library of trusted information you can use for future projects.

Before firing a project in your kiln, we recommend cleaning the top and bottom of each piece of sheet glass with a non-detergent glass cleaner and lint-free towels. Isopropyl alcohol or a mixture of 50% white vinegar to 50% distilled water should do the trick. Be careful of those edges, though!

Coat your kiln shelf and any slumping molds with kiln wash to prevent your glass from sticking. Follow the manufacturer’s recommendation for drying your kiln wash.

For full fuse projects, we recommend stacking two layers of 3mm Wissmach kiln glass on top of each other for best results. Results for projects that are thicker or thinner will vary.

When firing thicker projects (6mm and greater), we recommend a more conservative firing schedule. Thicker pieces require a slower initial heat and a longer annealing soak. Testing with a smaller project is encouraged before starting a larger one. And don’t forget to keep those notes!

We recommend fusing and slumping in two separate firings.

There is no uniform firing schedule for slumping your project. Different molds require different process temperatures, and hold times may vary depending shape and size of your mold and kiln style.

Tack fusing can give you many design effects. We recommend starting with a temperature of 1300°F/704°C, but have fun exploring temperatures slightly above and below for different results.

Casting project firing schedules and process soak times will vary based on object design, size, glass type, and kiln style.