榫卯Chinese Joinery
Stretchers & braces
赶枨
gǎn chéng

Gan Cheng (赶枨): Why Chinese Chair Stretchers Sit at Different Heights

Staggered stretchers · 步步高赶枨

Look at the stretchers under a Chinese chair: the front one is lowest, the sides higher, the back different again.

That is gan cheng, staggered stretchers, and it is about strength more than looks.

Chinese
赶枨 · gǎn chéng
Variant
步步高赶枨 (step-by-step higher)
Joins
Several stretchers to one leg
Found in
Chairs, stools, tables
Related
Big in, small out
Drag to rotate. Slide to take the joint apart, or press Assemble to watch it go together.

How it works

Spread the mortises

When stretchers from two faces meet one leg at the same height, their mortises meet inside it and weaken it. Staggering the heights spreads them out.

Chairs

Wang Shixiang: a chair’s four base stretchers are usually arranged with the front one low (it’s a footrest), the sides higher, and the back lower again. Another arrangement keeps rising front, sides, back: “step-by-step higher” (步步高赶枨).

How it's made

  1. Two stretchers
    Step 1

    Two stretchers

    Two stretchers meet one leg.

  2. One low
    Step 2

    One low

    One is set low.

  3. One higher
    Step 3

    One higher

    The other is set higher.

  4. Staggered mortises
    Step 4

    Staggered mortises

    The mortises sit at different heights.

  5. Stronger leg
    Step 5

    Stronger leg

    The leg isn’t weakened at one spot.

  6. Step-by-step higher
    Step 6

    Step-by-step higher

    The rising arrangement on chairs.

Variations

Same height

Where they must be level, as on cabinets, the tenons are cut big in, small out to pass each other.

In museum collections

Roundback armchair, 1600s–1700s: the front footrest stretcher sits lowest (Cleveland Museum of Art · CC0)
Roundback armchair, 1600s–1700s: the front footrest stretcher sits lowest
Cleveland Museum of Art

Questions

What is gan cheng?

Arranging stretchers at different heights so their mortises don’t meet inside a leg.

What is “step-by-step higher”?

Front lowest, sides higher, back highest.

What if they must be level?

Use big-in, small-out tenons that pass each other.

Further reading
  1. Wang Shixiang, 家具结构之结合 (excerpt), Sina Collection
  2. 十七/十八世纪 紫檀官帽椅一对, Christie's