Natsume Core Identification

Distinguishing Composite (wood-resin) vs Pure Resin Natsume Cores

Think of this not as a single test, but as a pattern of evidence. No one clue alone is decisive; several together usually are.

  1. Weight Feel, Not Just Weight

Both are consistent, but they feel different in the hand.

  • Composite core
    • Feels slightly warmer and more inert
    • Marginally heavier than pure resin at the same size
    • Less “hollow” sensation when rotated in the fingers
  • Pure resin
    • Feels lighter and more “plastic-neutral”
    • Often gives a faint sense of hollowness
    • Less mass concentration at the walls

? Collectors often describe this as “dead weight” (composite) vs “shell weight” (resin).

  1. Tap Sound: One Step Finer Than Wood vs Plastic

You already noted “dull vs resonant.” Here’s the refinement:

  • Composite core
    • Soft thud with micro-grain damping
    • Sound decays quickly but not abruptly
    • Feels absorbed rather than reflected
  • Pure resin
    • Sharper click or tok
    • Slightly higher pitch
    • Sound reflects rather than absorbs

? If wood is a note and resin is a click, composite is a muted knock.

  1. Rim & Foot Under Oblique Light (Very Telling)
    • Ultra-fine, matte, mineral-like surface
    • Sometimes faint speckling or micro-fibers
    • Edge looks cut, not molded
  • Pure resin
    • Glassy smoothness
    • Flow lines or rounding from mold release
    • Slight “skin” effect at edges

? A phone flashlight held sideways works better than direct light.

  1. Interior Wall Texture (Often Overlooked)

Especially visible inside the lid.

  • Composite
    • Slight tooth or chalky smoothness
    • Lacquer sits into the surface
  • Resin
    • Slick, sealed feel
    • Lacquer sits on top of the surface

If you lightly drag a fingernail (no pressure):

  • Composite = muted friction
  • Resin = gliding slip
  1. Manufacturing Precision vs Finishing Precision

This is subtle but culturally important.

  • Composite core
    • Shape precision comes from machining
    • Lacquer application shows human control
    • Common in mid-to-high tea practice ware
  • Pure resin
    • Shape precision comes from molding
    • Lacquer often sprayed or uniformly applied
    • Common in decorative or entry-level ware

This aligns with the production reality described in your article 

Tea Dogu Constant Contact Artic…

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Practical Summary Table

Feature

Composite Core

Pure Resin Core

Weight feel

Dense, inert

Light, shell-like

Tap sound

Soft thud

Sharp click

Rim texture

Mineral, cut

Glassy, molded

Interior feel

Slight tooth

Slick

Craft context

Tea-focused

Market-focused

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