Weld Extract

Weld extract, derived from the flowering plant Reseda luteola, is celebrated for producing the most vibrant and lightfast yellow dye available among botanical sources. Historically favored by tapestry weavers and textile artisans, weld remains an invaluable resource in natural dyeing for its vibrant yellow color that includes a subtle green undertone. When combined with indigo, weld offers a unique electric lime green hue, enhancing its versatility in dye applications. Alfa Chemistry's weld extract is expertly formulated to meet the demands of organic textile production.

Product Details and Packaging

Chemical Composition and Properties of Weld Extract

Weld extract primarily contains luteolin (C₁₅H₁₀O₆), a flavonoid compound responsible for its intense yellow color. The concentration of luteolin in weld extract contributes to its exceptional colorfastness and high stability under light exposure, ensuring lasting vibrancy in dyed materials. The unique chemical profile of weld also includes minor flavonoid constituents, which contribute to the greenish hue that weld imparts, especially when mordanted with specific metallic salts such as iron.

• Solubility: Water-soluble; solubility enhanced in slightly alkaline solutions
• Lightfastness: Excellent, especially in comparison to other botanical yellow dyes

Application Techniques for Optimal Color Development

Weld extract can be applied in various ways to achieve a spectrum of yellow hues, ranging from warm golden tones to deep chartreuse. The application of weld extract requires precise handling to maximize color yield and stability. Alfa Chemistry's high-grade weld extract is extremely potent and provides robust color results, allowing a small amount to dye a substantial quantity of fiber.

Recommended Dyeing Methods

A. Standard Yellow Dye Bath: Dissolve weld extract in hot water, maintaining a pH-neutral or slightly alkaline environment by adding calcium carbonate. This enhances the brightness and stability of the dye. Use a pinch of soda ash to intensify the yellow hue, which yields a rich and saturated color that adheres well to natural fibers.

B. Green and Lime Tones with Mordants: When combined with an iron mordant, weld extract develops a rich chartreuse. For lime green tones, the weld can be overdyed with indigo, providing a unique layered color effect that is both bold and refined. This effect is especially valued in eco-friendly fashion and textile design for its naturally derived but visually striking qualities.

C. Enhanced Color Fastness with Post-Bath Treatment: A post-dye bath in a mildly alkaline solution, such as ammonia, further enhances the yellow vibrancy and colorfastness. This technique is particularly effective for textiles intended for prolonged exposure to light, such as tapestries and upholstery.

It is important to note that our products are for research use only and are not for clinical use.