JUMA®: origins and identity of a benchmark material

Developed in Germany by Richter & Hopf, JUMA® is a high-density polyurethane-based composite material designed to meet the requirements of craftsmen working with noble materials. Its name is a registered trademark guaranteeing rigorously controlled manufacture and certified composition. Since its appearance in European cutlery workshops, it has established itself as the most serious technical and aesthetic alternative to natural ivory: same creamy appearance, same slightly warm feel, same polishing possibilities - without the restrictions associated with protected species. Today, it is used by cutlers all over Europe, both for handcrafted products and for limited series with high added value.

JUMA® properties and technical features

JUMA® offers a range of technical features that make it particularly well-suited to artistic and semi-industrial cutlery.

Machinability and processing

JUMA® can be worked with conventional cutlery tools: drill press, milling machine, sanding disc, dremel. Thanks to its homogeneous structural composition, it does not splinter when cut, which considerably reduces the risk of breakage when drilling rivet holes. It can also be thermoformed in boiling water for curvature adjustments.

Surface, hardness and strength

The surface of JUMA® is dense and very hard, making it highly resistant to abrasion and everyday scratches. It is insensitive to oils, greases, diluted acids and common cleaning agents - an essential quality for a handle intended for use in the kitchen or workshop. It absorbs virtually no water, guaranteeing long-term dimensional stability, even in humid environments.

Colors and patterns

The JUMA® range is distinguished by its wide range of patterns: plain ivory imitation, snakeskin, pearl, camouflage, wood, carbon, and many solid colors. Each reference is produced in homogeneous batches, so you can order several plates with a consistent visual appearance from one piece to the next.

How to choose JUMA® for a knife handle?

JUMA® is suitable for all levels of cutlery, from the beginner looking for a material that's easy to work with to the expert who wants a top-of-the-range finish with maximum reliability. Here are the criteria to consider before choosing your reference:

• Pattern: opt for imitation ivory or mother-of-pearl if you're looking for a sober, elegant finish; camouflage or snake patterns are more suited to hunting knives and character pieces.
• Thickness: Mercorne inserts are available in several standard thicknesses - check the dimensions of your tang before ordering.
• Blade type: JUMA® works equally well with stainless steel, carbon steel or damascus. Its timeless appearance does not visually compete with the blade.
• The finish you want: JUMA® can be water-polished to a mirror-like shine, or left satin-finished for a more matt feel. It can also be waxed or varnished.
• The budget: JUMA® is positioned in the premium technical materials range, at an affordable price compared to ivory or fossil materials.

Mercorne and JUMA®: 34 years of careful selection

Mercorne has been distributing JUMA® for several years, and offers one of the most comprehensive ranges available in France, with over 50 references in permanent stock. Each insert is cut in our workshop at La Monnerie-le-Montel (Puy-de-Dôme), to standard cutlery formats, with systematic quality control before dispatch. Orders are dispatched the same day (D+0 for orders placed before 12 noon), with free delivery for orders over €90. Returns are accepted within 15 days. Our team - and Olivier in particular - will be happy to advise you on the choice of pattern, thickness or application techniques best suited to your project.

Frequently asked questions about JUMA®

Is JUMA® as beautiful as natural ivory?

JUMA® is designed to faithfully reproduce the look and feel of ivory. It has the same creamy, slightly translucent surface appearance, and can be polished to a comparable gloss. For the vast majority of cutlery applications, it is visually indistinguishable from quality synthetic ivory.

Can JUMA® be painted or stained?

JUMA® can be waxed, varnished or treated with products for hard synthetic materials. However, conventional penetrating stains (for wood or bone) do not adhere to polyurethane in the same way. For surface finishes, water polishing with progressive abrasives (400 → 800 → 1500 → 3000) gives the best results.

Is JUMA® suitable for food contact?

JUMA® is resistant to fats, oils and common cleaning products. Its certification of conformity [À VÉRIFIER : mention food-contact spécifique à confirmer avec Richter & Hopf] makes it a suitable material for kitchen knives, provided that the assembly and fastenings are also compliant.

What's the difference between JUMA® and other composites such as G10 or Micarta?

G10 and Micarta are composites based on fiberglass or resin-impregnated fabric - chosen above all for their robustness in intensive use. JUMA®, on the other hand, is a high-density polyurethane with a focus on aesthetics: it imitates noble materials (ivory, mother-of-pearl, skin), with an emphasis on visual appeal and feel. The two families are complementary, depending on the intended use.

Is JUMA® easy to work with for beginners?

Yes - that's one of its major assets. Its homogeneous composition prevents splintering when cutting, and its predictable behavior with sander and polisher makes it accessible right from the first knives. This material is recommended for learning handle finishing techniques, before moving on to more delicate materials such as fossils or mammoth ivory.