Welcome to the Laboratory
This page is a small window into our approach here at Molten Aura Labs. We are advancing the state of the art of borosilicate color creation and we’re glad to join you on your journey of advancing the state of your art.
How is your glass unique?
Every element we use in the glass affects it’s working characteristics in some way. Having complete control over the composition allows us to minimize undesirable traits while maximizing color saturation and usability. No colored glass is going to work exactly like its clear counterpart. Many clears don’t even behave exactly the same. However, we go to great lengths to ensure that the balance of CTE (Coefficient of Thermal Expansion) and viscosity ensures compatibility with the NIST Borosilicate standard (3.3 x 10-60).
Why make borosilicate colors from scratch?
In addition to enhanced saturation levels, in many cases we are able to improve the working properties, stabilize the compositions, and minimize, if not eliminate all air (seeds). Overall, the glass is superior in quality to re-melted colorized cullet because the elements are fully integrated into the glassy network.
Our vision is to propel a new generation of borosilicate artwork forward with the richness and optical clarity that has been a staple in soft glass for centuries. We see SANDCRAFTED® glass as the logical next frontier for discerning borosilicate artists.
This all sounds expensive. Are these going to cost more than my usual colors?
Yes (for now). This new process is time and energy intensive and requires completely customized equipment, tools, and furnaces. We run a very lean operation and we’re continually learning new approaches and optimizing our processes.
Some colors contain expensive elements, such as gold. Those colors will typically have a higher price point, no matter how they are made.
That being said, you can easily thin our colors out by layering clear over or under them and they will still look amazing. You can effectively double or even triple your yield by adding clear, and your piece will still look more saturated than many other pinks and purples on the market.
Why do your colors require different annealing temperatures than Simax? Does that mean they are not 33CTE?
The coefficient of thermal expansion is only one factor in getting two different materials to seal together. A perfectly matching CTE does not automatically equal “compatibility”. But at the same time, something slightly higher or lower than the specific CTE measurement can still compatibly seal to something else (it doesn’t even have to be glass to glass). So when we, or any other company, speaks of 33CTE glass, it is generally understood to represent a family of colored and non-colored borosilicate that is compatible in the area of ~3 × 10−6 K−1 at 20°C. In fact, “borosilicate” itself is an amazingly broad term that includes a huge spectrum of glasses with a vast range of CTE values, viscosities, opacities, etc., most of which are not at all compatible with Simax.
We are not using or making clear Simax, but starting from sand. As an example, something like Lotus White is obviously a radical departure from a simple clear. However, despite it’s unique viscosity curve and CTE measurements, it can still be made to be compatible with Simax. We consider colored glass as unique from clear glass. This is a paradigm shift for most glassblowers, and many manufacturers who typically start with clear and add things to it.
So, viscosity can be different, and CTE can even be different (within reason), and the glass can still be compatible. However, this also means that the annealing/strain temps are different (within reason). “Proper” annealing means there is zero stress left when viewed under a polariscope. “Successful” annealing may mean that your piece stayed together – though there may still be residual stress you haven’t completely relieved.
Ultimately, the glass performing for an individual for their desired effect is what matters most. These balancing acts are not unique to glass making. Metals, ceramics, glasses, plastics, foods, etc. are all formulated as well as they can be within their respective constraints. Anyone exploring the formulation of “different but compatible” materials will quickly learn of the endless variables that need to be accounted for and balanced.
Lotus White, Moonstone, Neptune, Plantphibian, Gold Ruby, Gold Amethyst, Telemagenta, and Royal Jelly have been tested by Orton Materials Testing and Research Center for exact strain point, annealing point, and CTE (Coefficient of Thermal Expansion). We use these data to help us dial in the formulas, and provide accurate annealing temperature ranges for end users.