Jeongja-sal

This engine recreates Jeongja-sal (井字箭), where both vertical and horizontal slats fill the frame completely to form a grid. The name comes from 井, the character for "well," which the woven shape resembles — an even, gapless grid is the face of this changho. Also called man-sal (滿箭), it was the second most common form after Se-sal. It shares most of its sidebar structure with Se-sal (door settings, dimensions, lattice settings, finish, background, export), but uses a single-ratio even grid instead of three top/middle/bottom zones, and adds a random pattern feature that reshuffles the grid.

How It Differs from Se-sal

	Jeongja-sal	Se-sal
Zoning	One cell ratio applied across the whole grid	Split into top/middle/bottom, each with its own cell count and ratio
Vertical ratio range	1.0 – 3.0	1.0 – 5.0
Random pattern	Yes (Mondrian-style random division)	No
Auto-fit height	Yes	No

Main Parameters

Item	Description
Door type / panels	Hinged or sliding, 1–4 panels. As with Se-sal, frame thickness and clearance are applied automatically to calculate the real panel dimensions.
Frame width / height	Wall opening dimensions (400–3,000mm). The outer panel size is calculated with the frame thickness removed.
Horizontal cells	Number of horizontal grid divisions
Vertical ratio	1.0–3.0. Sets each cell's width-to-height ratio, from which the vertical cell count is derived automatically.
Auto-fit height	When checked, the frame height is adjusted automatically so the last grid row meets the bottom rail exactly.
Stile / rail thickness	Outer frame thickness (mm)
Slat thickness	Cross-section thickness of the lattice slats (mm)
Use transom panel	Adds a transom panel zone at the top when checked; its height is set separately
Show dimensions / door frame	Choose whether measured dimensions and the frame outline appear on the canvas

Combining the horizontal cell count with the vertical ratio lets you tune the grid freely — from perfectly square cells to tall, narrow ones.

Random Pattern

Unique to the Jeongja-sal engine, this re-divides the even grid at random, Mondrian style.

Button	Function
Generate random	Randomly merges and splits cells from the current grid to create an irregular pattern
Reset	Clears the random pattern and restores the original even grid

Each click produces a different result. Save as soon as you get one you like — previous results are not kept, and reset discards the current one.

Production Specification & Parts List

The same items as Se-sal are calculated and displayed automatically: frame width/height, outer and inner width/height, horizontal cell count, horizontal and vertical layout lines, eye size, half-lap width and stile groove width. The parts list is ordered as horizontal and vertical slats, frame members, the transom panel (if used), and the door frame.

Finish & Color

Wood, finish and hardware options, along with frame and slat colors, are the same as Se-sal. Panel fill also works here — click a grid cell to fill that individual panel with color. (Panel fill is currently disabled in the Bit-sal, Gyeokja-bit-sal, Semo-sotgeul-sal and Yukmo-sotgeul-sal engines.)

Example Uses

Sliding changho in contemporary hanok
Partition changho for cafés and commercial spaces
Irregular changho designs made with the random pattern