1. Observation method: Look at the grain and gloss
Genuine leather
Grain: The surface grain is naturally irregular, and the grain of the same material is different in different areas (such as irregular dot distribution of cow pores), and some natural leather scars are retained (such as mosquito bite marks).
Gloss: The gloss is soft and not glaring. After long-term use, the surface will form a natural "patina" due to friction.
Cross section: Natural fibrous structure, the stratification is not obvious, and there will be fine fibers loosened by pinching with fingers.
Full PU leather
Grain: The surface grain is highly uniform (such as uniform lychee grain and cross grain), similar to the mechanical sense of "copy and paste".
Gloss: The gloss is bright or dull, and some imitation leathers will be deliberately matte treated, but lack the warmth of genuine leather.
Cross section: Obvious layered structure, the surface layer is coating, the bottom layer is base fabric (non-woven fabric or knitted fabric), the edges are neat and there is no exposed fiber.
Semi-PU leather
Grain: The naturalness of the grain is between genuine leather and full PU. Some products will imitate the "irregularity" of genuine leather, but there is still regularity when you look closely (such as the scales of the imitation crocodile grain are arranged more neatly).
Gloss: The gloss is medium, and some are close to the texture of genuine leather through surface treatment (such as matte coating).
Cross-section: The base fabric layer is usually a paper or thin fiber layer, which is thinner than full PU. There may be slight burrs at the junction of the coating and the base fabric.
2. Touch method: Perceive the feel and elasticity
Genuine leather
Feel: Soft and resilient, with a slightly "astringent" feeling on the surface (due to natural oil residue), the wrinkles are natural after bending and can rebound slowly.
Temperature: The temperature conducts slowly when close to the skin, and it feels warm.
Full PU leather
Feel: The texture is hard or too smooth (similar to plastic), the wrinkles are stiff after bending, and some inferior products have a sticky feeling.
Temperature: Fast heat conduction, feels cold when touched, and feels harder in winter.
Semi-PU leather
Hand feel: Softness is close to genuine leather, but the elasticity is slightly weaker. The wrinkle recovery speed after bending is slow. The surface may have a slight grainy feel (from the coating process).
Temperature: The thermal conductivity is between genuine leather and full PU. The hand feel is gentle but not as warm as genuine leather.
3. Burning method: Smell and observe the burning state
(Note: It needs to be operated in a safe environment to avoid the danger of open flames!)
Genuine leather
Burning phenomenon: After ignition, it burns slowly, the flame is yellow, and it emits a burnt smell similar to burning hair (protein burning smell) when burning.
Burning residue: After burning, it forms fragile black granular ash, which can be crushed into powder by lightly pressing with fingers.
Full PU leather
Burning phenomenon: After ignition, it burns quickly, the flame is blue, accompanied by a lot of black smoke, and emits a pungent smell of plastic (PVC) or chemical agents.
Burning residue: After burning, it forms hard and brittle black agglomerates, which are difficult to crush after cooling, and the surface is sticky.
Semi-PU leather
Burning phenomenon: The burning speed is slow, the flame is yellow, and there may be a slight plastic smell in the early stage (because it contains some chemical coatings), but there is no obvious black smoke.
Burning residue: gray-white or light brown ash is formed, the texture is crisp, and some products have a small amount of lumps (depending on the base fabric material).
4. Water drip method: test water absorption
Genuine leather
Performance: Water drops on the surface will slowly penetrate, and water marks can be seen spreading within 30 seconds (because the pores of genuine leather are breathable).
Full PU leather
Performance: Water drops are attached to the surface in beads and do not penetrate for a long time (the coating completely closes the surface), and water drops can slide directly when the material is tilted.
Semi-PU leather
Performance: Some semi-PU surfaces have microporous structures, and water drops will slowly penetrate (the penetration rate is slower than genuine leather), but inferior products may have similar performance to full PU.
5. Pressing method: observe pressing marks
Genuine leather
Performance: Pressing the surface with a finger will cause a depression, and the depression will slowly rebound after release, leaving slight wrinkles (similar to skin elasticity).
Full PU leather
Performance: After pressing, the depression rebounds immediately, without obvious wrinkles, or leaving a rough pressing mark (due to the poor elasticity of the material).
Semi-PU leather
Performance: After pressing, the depression rebounds at a medium speed, and may leave shallow temporary wrinkles, which take a few seconds to return to flatness.
Summary: Quick identification formula
Genuine leather: messy grain, soft flesh, burnt smell, no slipping when dripping water penetrates.
Full PU: neat grain, hard leather, pungent smell, impervious to water and fire, poor elasticity.
Semi-PU: grain is like genuine leather but orderly, mild to the touch, slow to burn, and water absorption is between the two.
