Difference between revisions of "Embossed leather"
(→The embossing of leather) |
(→The parameters that influence the embossing:) |
||
| Line 41: | Line 41: | ||
| − | Prior to embossing, leather may be [[Leather lamination - Laminating leather|bonded with foam and lining on the back]] so that the embossed pattern sits neatly and retains its depth. Sometimes a fabric is glued to the back to prevent stretching and flattening of the embossed motif. Deeply imprinted motifs need to be | + | Prior to embossing, leather may be [[Leather lamination - Laminating leather|bonded with foam and lining on the back]] so that the embossed pattern sits neatly and retains its depth. Sometimes a fabric is glued to the back to prevent stretching and flattening of the embossed motif. Deeply imprinted motifs need to be stabilised with fillers. There is a wide variety of filling materials that can be used, from papier mâché to hot glue, but the decisive factors are their stability and flexibility. |
Revision as of 10:56, 16 March 2017
Contents
The embossing of leather
Embossing is the art of producing raised patterns on the natural grain of an animal skin. The design is created by pressing rolling, or stamping. Embossments can cover the entire surface of a skin or just selected areas.
Types of embossing
- Blind Embossing, blind printing, blind finishing: Embossing of leather without colour.
- Gold embossing: The transfer of gold leaf into the embossing.
- Colour imprint: The transmission of colour by colour films in the embossment.
Different embossing on book covers: Blind Embossing - Gold embossing - Colour imprint.
The parameters that influence the embossing:
- The amount of pressure used to stamp the tools into the leather -> The higher the pressure, the stronger and more durable the embossing.
- The time required for the stamping -> The longer the stamping pressure, the stronger and more durable the embossing.
- The temperature used -> The hotter the tool, the stronger and more durable the embossing.
- The moisture content of the leather -> Imprints in damp leather are clearer and more durable.
Prior to embossing, leather may be bonded with foam and lining on the back so that the embossed pattern sits neatly and retains its depth. Sometimes a fabric is glued to the back to prevent stretching and flattening of the embossed motif. Deeply imprinted motifs need to be stabilised with fillers. There is a wide variety of filling materials that can be used, from papier mâché to hot glue, but the decisive factors are their stability and flexibility.
Embossing after pigment colouration. The fold was not embossed.
Roller of an embossing machine in a leather factory.
Embossing plates: coarse grain leather and pig skin grain.
Crocodile pattern by embossing plate.
Embossing stamps are milled. VOLVO-Logo embossed in car leather (www.ledermanufaktur.com). - Embossing in a Porsche.
Embossing in the imitation leather of a Ford Mustang.
Due to the longer exposure time at a hydraulic press, the embossed motif is more stable than if it was applied with a roller. Depending on the temperature, pressure and length of time, the embossing is more or less clear and stable. Moisturising the leather afterwards stabilises the motifs.
The process needs to be fine-tuned to achieve good results. Too hot embossed aircraft leather is not good enough for "First Class".
Embossing rollers and embossing stamps are expensive. Individual motifs are therefore often carved. It is also possible to create motifs on leather with lasers.
Embossed furniture leather.
Embossed lamb leather used for clothing.
Beautiful embossing on a strap made of elkskin leather (Pineyard - MUD GbR).
Almost any type of leather can be embossed. However, the embossing must be adjusted, depending on the type of leather. The resistance of an embossing depends on the embossing process. The higher the pressure and the temperature, and the more moisture in the leather, the more permanent the reshaping of the fibre. But, of course, there are also limits to the pressure and temperature that can be applied to each leather.
Reasons for embossing leather: To provide leather with designs
Often, leather is decorated to achieve a certain look. The grain structure of other animals can also be copied. It is sometimes difficult to distinguish even for experts if the grain structure is original from the animal or only an embossed copy.
A video about painting on leather, perforating leather, carving leather, embossing leather and several other methods to create motifs on leather.
|
165px | 
|
| Embossed leather belt. | Embossed seat cushion. | Embossed antique weapon shield. |
| 165px | 
|
|
| Embossed case. | Embossed and decorated with paint. | Embossed skin structure of ostrich leather. |
|
165px | 
|
| Embossed antique leather. | Beautiful motif. | Very finely worked. |
|
165px | 
|
Antique leather folder from 1920 with beautiful embossing.
Leather handbags producers like to brand by embossing their company logos.
Antique leather chairs are often decorated with beautiful motif.
Modern patterns embossed in cow leather.
Front and back side horse motive embossing.
Horse stamping tool positive and negative as pictures above. - Two other variants of horse motifs as embossing tool.
Usually, Embossing is done on the grain side by compressing the leather grain structure. The uncompressed leather fibres remain above. This creates a three-dimensional effect. Leather is sometimes embossed with two embossing plates from both sides (positive and negative). Then the recesses on the back must be stabilized to not press done the embossed motif in use.
In case of strong embossments in soft leathers, these are stabilized from the back by a silicone filling to avoid that the embossing cannot be pressed down from the front.
From behind stabilized embossing of leather jackets.
Antique Leather with a wax based reinforcement (wax mixed with sand) at the back side.
Very exotic: Cow leather with an extremely strong embossing and metallic effect.
Unusually strong deformation of furniture leather.
Embossed suede.
Crocodile embossing in Imitation leather.
Reasons for embossing leather: Correction of the leather grain pattern
Another reason for the embossing of leather hides is to hide natural markings on leather. Therefore, the surface is sanded, repaired and embossed. Such leather is called ‘corrected grain’.
A farmer doesn’t get any more money from the butcher for his cows and cattle, if the skin is flawless. During their lifetime, animals suffer wounds and marks that affect the quality of the leather surface. To hide insect bites, injuries, illnesses and other damages on animal skins and to create a uniform grain, cattle hides are embossed.
This reduces wastage of leather, as the entire surface of a skin gets a uniform grain pattern. All parts of a set of furniture or car interiors will be identical. Minor flaws and irregularities of the natural grain can be balanced and must not be circumvented when cutting the leather.
Leather grain texture
A natural leather grain is different across the skin surface. In the middle of a skin the leather is mostly fine grained, and toward the edge it is coarse grain.
When cutting seating surfaces for furniture and vehicles, the customers value a uniform grain structure. Due to the uniform embossing, the grain structure is identically all over the hide.
On one hide: fine grain - transition - coarse grain.
Un-embossed leather
For any tannery, the number of hides which can be used can usually raise and lowers costs. Skins that are not good enough for processing as full-grain leather can be embossed. Only about 10-20% of the hides coming from the slaughterhouse are ‘good’ to ‘very good’ quality. Embossing does not reduce the quality of the leather. As long as no damage is hidden under the embossing that affects the life expectancy of the leather, they are perfectly normal.
Un-embossed leather. - The hair pores are still visible (click to enlarge).
Corrected Grain - sanded and embossed leather
As preparation for embossing, the leather is mostly sanded to obtain a uniform structure. Such leather is called ‘Corrected Grain’. Such leather is cheaper and is more plastic like and colder. The breathability of such leather is significantly lower when compared with porous leathers. There is also leather which is only lightly sanded making it soft and warm to touch. But this is more the exception.
Embossed and sanded leather. - The hair follicles are sanded away and over embossed.
Embossed leather without sanding
To prevent lower quality hides being sanded and embossed, sanding in some cases is forbidden by the car manufacturer.
Embossed, but not sanded leather. The hair pores are still clearly visible.
Car leather from BMW with "Montana" embossment. - Strong embossed furniture leather. - BMW with "Picasso" embossment.
Other possibilities how to provide leather with designs
- Carving leather
- Laser engraving - Laser cutting leather
- Perforated leather
- Hole punching
- Embroidery
- Leather seams
- Leather imprint
- Formed leather
- Painting on leather
- Braided leather
- Leather etching & engraving
- Leather tattoo
- Glued leather strips
- Burning designs on leather
Additional information
a kotori web solution
