The Amber Purple family is one of the most fascinating and highly sought-after color ranges in the world of borosilicate glass. Originally developed by Suellen Fowler during her time at Pepperdine University and later passed on to the founder of Northstar Glassworks, this range has become a benchmark among so-called “striking” colors. What makes Amber Purples so unique is their ability to produce a wide variety of visual effects depending on working conditions, temperature, and application. They can reveal deep, shifting, and sometimes unexpected tones, making this palette especially valued by glass artists for its richness and its unpredictable nature.
Five colors, five styles
Each color in the Amber Purple range is designed for a specific application as well as a particular “strike” behavior. The NS-013 Amber Purple, the original shade, is ideal for thick blown glass work as well as sculptural pieces. The same applies to NS-48 Light Blue Amber Purple. The other three shades (NS-026 Double Amber Purple, NS-049 Dark Blue Amber Purple, and NS-069 Green Amber Purple) are more versatile. The darker tones can also be used for sculpture, but they offer greater flexibility and are better suited for thinner applications.
The most important parameter for achieving a good purple strike is flame adjustment. Amber Purples should never be worked in a reducing flame. Instead, a clean, well-balanced oxidizing flame must be used. If the flame is not sufficiently oxidizing, the color may become opaque and take on a milky yellow tone.
During initial heating, a thin metallic haze appears on the surface of the glass. This is a deposit of metallic silver that rises to the surface of the material. If work continues before this haze is completely removed, it may thicken and form a matte gray layer, masking the true color.
To achieve the true “purple strike”, it is necessary to heat aggressively with a strong and precise flame in order to fully remove this initial deposit. The piece must be slowly rotated in the flame to evenly “clean” the surface. The glass can be heated to a very high point, close to surface boiling: even if the flame temporarily marks the glass, the color will stabilize afterward. This step is essential in the process.
Once this initial haze layer is removed, it may reappear, but less intensely. It can then be burned off more easily with a less aggressive heat. On the more reactive shades (such as NS-026 Double Amber Purple and NS-069 Green Amber Purple), extra attention is required as the haze can return more quickly.
For striking Amber Purples, two methods are possible: flame working or kiln striking (kiln).
- For optimal flame results, it is recommended to slightly cool the piece after removing the haze, then reintroduce it into a soft, neutral flame until the color gradually appears. This cycle can be repeated to intensify the tone in a controlled way. Excessive heating may lead to over-striking or the return of haze.
- Flame striking is best suited when gradients or color variations are desired. In contrast, to achieve a uniform and stable color throughout the glass, kiln striking is preferable. In this case, the unstruck glass is placed in the kiln at around 1125–1150°F (approximately 607–621°C) for about one hour, until the desired intensity is reached. However, caution is needed with thin pieces, as they may slump at these temperatures.
The layering effects: color superposition
“Layering”, or the superposition of glass layers, is one of the most powerful techniques for fully exploring the Amber Purple family. It allows the final appearance of a color to be modified, enriched, or completely transformed.
NS-54 Star White: intensification and depth
Star White acts as a visual amplifier. When used as a base layer or an intermediate layer, it enhances the brightness and depth of Amber Purple colors, giving them greater contrast and sharpness.
NS-09 Yellow: warming toward amber
Yellow helps shift the palette toward warmer tones. When combined with Amber Purple, it creates rich amber effects with golden highlights and a strong sense of internal glow.
NS-45 Blue Moon: cool contrast
In contrast, Blue Moon introduces a cool and deep visual balance. It helps stabilize or offset overly warm compositions while creating very interesting effects of visual depth.
Orange and Ruby: “fire” effects
Orange and Ruby colors create vibrant and dynamic effects. They enhance warm tones and produce visual compositions reminiscent of fire or lava, making them especially expressive in sculptural work.
Source : Northstar Glassworks
The Amber Purple family is one of the most fascinating and highly sought-after color ranges in the world of borosilicate glass. Originally developed by Suellen Fowler during her time at Pepperdine University and later passed on to the founder of Northstar Glassworks, this range has become a benchmark among so-called “striking” colors. What makes Amber Purples so unique is their ability to produce a wide variety of visual effects depending on working conditions, temperature, and application. They can reveal deep, shifting, and sometimes unexpected tones, making this palette especially valued by glass artists for its richness and its unpredictable nature.
Five colors, five styles
Each color in the Amber Purple range is designed for a specific application as well as a particular “strike” behavior. The NS-013 Amber Purple, the original shade, is ideal for thick blown glass work as well as sculptural pieces. The same applies to NS-48 Light Blue Amber Purple. The other three shades (NS-026 Double Amber Purple, NS-049 Dark Blue Amber Purple, and NS-069 Green Amber Purple) are more versatile. The darker tones can also be used for sculpture, but they offer greater flexibility and are better suited for thinner applications.
The most important parameter for achieving a good purple strike is flame adjustment. Amber Purples should never be worked in a reducing flame. Instead, a clean, well-balanced oxidizing flame must be used. If the flame is not sufficiently oxidizing, the color may become opaque and take on a milky yellow tone.
During initial heating, a thin metallic haze appears on the surface of the glass. This is a deposit of metallic silver that rises to the surface of the material. If work continues before this haze is completely removed, it may thicken and form a matte gray layer, masking the true color.
To achieve the true “purple strike”, it is necessary to heat aggressively with a strong and precise flame in order to fully remove this initial deposit. The piece must be slowly rotated in the flame to evenly “clean” the surface. The glass can be heated to a very high point, close to surface boiling: even if the flame temporarily marks the glass, the color will stabilize afterward. This step is essential in the process.
Once this initial haze layer is removed, it may reappear, but less intensely. It can then be burned off more easily with a less aggressive heat. On the more reactive shades (such as NS-026 Double Amber Purple and NS-069 Green Amber Purple), extra attention is required as the haze can return more quickly.
For striking Amber Purples, two methods are possible: flame working or kiln striking (kiln).
- For optimal flame results, it is recommended to slightly cool the piece after removing the haze, then reintroduce it into a soft, neutral flame until the color gradually appears. This cycle can be repeated to intensify the tone in a controlled way. Excessive heating may lead to over-striking or the return of haze.
- Flame striking is best suited when gradients or color variations are desired. In contrast, to achieve a uniform and stable color throughout the glass, kiln striking is preferable. In this case, the unstruck glass is placed in the kiln at around 1125–1150°F (approximately 607–621°C) for about one hour, until the desired intensity is reached. However, caution is needed with thin pieces, as they may slump at these temperatures.
The layering effects: color superposition
“Layering”, or the superposition of glass layers, is one of the most powerful techniques for fully exploring the Amber Purple family. It allows the final appearance of a color to be modified, enriched, or completely transformed.
NS-54 Star White: intensification and depth
Star White acts as a visual amplifier. When used as a base layer or an intermediate layer, it enhances the brightness and depth of Amber Purple colors, giving them greater contrast and sharpness.
NS-09 Yellow: warming toward amber
Yellow helps shift the palette toward warmer tones. When combined with Amber Purple, it creates rich amber effects with golden highlights and a strong sense of internal glow.
NS-45 Blue Moon: cool contrast
In contrast, Blue Moon introduces a cool and deep visual balance. It helps stabilize or offset overly warm compositions while creating very interesting effects of visual depth.
Orange and Ruby: “fire” effects
Orange and Ruby colors create vibrant and dynamic effects. They enhance warm tones and produce visual compositions reminiscent of fire or lava, making them especially expressive in sculptural work.
Source : Northstar Glassworks