> For the complete documentation index, see [llms.txt](https://help.clabassistant.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.clabassistant.com/size-grading/grading-rules.md).

# Grading Rules

Once a Size Chart has been created and assigned to your project, you can define grading rules to control how each point on the pattern changes across different sizes.

Available grading tools depend on your active subscription.

### Assign a Size Chart Before Grading

Assign a chart you have created for the project’s **Pattern Type** before defining grading rules. These rules control how Clab grades the pattern across the sizes in your chart. You can reuse a configured chart by assigning it to other patterns with the appropriate Pattern Type.

1. Click **Assign/Manage Size Chart** button in the top bar
2. Select the Size Chart you want to use
   * When assigning a **Size Chart Template**, you can enable the **Assign and Edit Template** switch to edit the template directly
3. Click on **Assign** button
4. Activate **Grading mode** (Ctrl/Cmd + G) to start editing rules

{% hint style="info" %}
IMPORTANT: if you have just created a new **Size Chart Template**, you must assign it with this switch enabled in order to define the template grading rules.
{% endhint %}

The Grading Settings panel will open and display:

* The active Size Chart
* The Sample Size defined in the anatomical set

***

### Select a grading point

1. Click a point on the pattern where grading should be applied.\
   Eligible grading points are shown along the edges of pattern pieces.
2. When a point is selected, it appears as an active grading point in the preview.

If multiple points overlap in the same position, selecting one of them will include the entire group. Use **Shift + click** on a grading point to adjust the selection, or hold **Shift** and drag from empty preview space to select several grading points. **Ctrl/Cmd + A** selects all grading points when no pieces are selected.

To select a whole piece instead, use **Shift + click** on its body. With at least one piece selected, **Ctrl/Cmd + A** selects all visible pieces so you can rotate them together. See [Rotate and arrange pieces while grading](#rotate-and-arrange-pieces-while-grading).

For multiple selected points, the panel lists their names. Choose a point with an existing rule as the **Source**, then use the apply button to copy that rule to the selected points. Points marked **No rule** cannot be used as a source. Remove a point from the selection with its **×** button.

The **Grade Rule** panel opens and displays:

* The grading point **Name**
* The list of sizes from the assigned Size Chart
* Input fields for **dx** and **dy** values

***

### Grading rules table

* The Sample Size row is always set to `0,0` and cannot be edited.
* Units follow **Grading Mode** in [User Preferences](/getting-started/main-menu.md#user-preferences): **mm**, **cm**, or **in**.
* Changes are saved **automatically** as soon as a value is confirmed by pressing Enter.

#### Enter grading values

* Click a cell in the **dx** or **dy** column and enter a value.
* Press **Enter** or **Tab** to confirm.
* The value is saved immediately and applied to the preview.

In the standard X/Y editor, **dx** and **dy** follow the horizontal and vertical axes shown in the preview. If you align or rotate a piece, the displayed values adapt to its orientation. Rules edited in that orientation remain consistent when you reset the piece to its original position and orientation.

Values are applied symmetrically:

* Larger sizes use the entered value
* Smaller sizes use the opposite sign

**Examples**

* Entering `-6` in the **dx** column for a smaller size applies `-6` to all smaller sizes and `6` to all larger sizes.
* Entering `-2` in the **dy** column for a larger size applies `-2` to larger sizes and `2` to smaller sizes.

***

#### Quick column actions

The grading table provides additional shortcuts:

* **Fill column**\
  Press `Shift + Enter` or `Cmd/Ctrl + Enter` to fill the entire column, automatically inverting values beyond the sample size.
* **Invert dx / Invert dy values**\
  Use the column header buttons to reverse the direction of the rule.
* **Reset rules**\
  Reset all values to `0,0`
* **Undo / Redo**
  * `Cmd/Ctrl + Z`
  * `Cmd/Ctrl + Shift + Z` (or `Cmd/Ctrl + Y`)

{% hint style="info" %}
The `dd` (diagonal distance) column is informational only and cannot be edited.
{% endhint %}

***

### Show one size at a time

Click a size name in the **Grade Rule** table to show only that size in the preview. The selected button uses the size's color. Click another size to switch, or click the active size again to show all sizes.

The isolated size has a colored fill and fully visible outlines. Selecting the sample size restores its normal piece appearance.

Grading points remain visible and selectable. You can move between points, edit their rules, and use directional grading with the same point markers and axes. Deselecting a point keeps the isolated size visible; select another point to continue working.

This is a preview setting: it does not remove sizes or change the chart's rules or exported size range. Leaving Grading mode restores the normal view.

***

### Editing individual sizes

If some sizes require non-linear or irregular grading:

* Click the **dx** or **dy** cell for the size you want to edit
* Enter a custom **dx** or **dy** value

Each cell can be edited independently.

***

### Stack Point (grading anchor)

A Stack Point locks one reference point per piece, making all other grading values relative to it.

* Activate with `Alt + Click` on a point or by using the **Stack Point** button on preview sidebar.
* You can also right-click a grading point and choose **Set stack point** when no more than one point is selected.
* To limit the stack to a single axis (X or Y):
  * `Cmd/Ctrl + Alt + Click` on the point, or
  * `Cmd/Ctrl + Alt + K` with a point selected.
* Repeat the action on the same point to disable it.

Stacked points are marked with a **STACKED** badge in the left Grade Rule panel.

Activating Stack Point from the sidebar or point context menu exits the active proportional grading tool before setting the anchor. If the sidebar action has no target point, select the point after activating the tool.

***

### Copy and paste grading rules

To reuse existing rules:

1. Select the source grading point.
2. Click **Copy**.
3. Select one or more target points.
4. Click **Paste**.

You can also paste selectively:

* Paste only **X** or **Y** values
* Use `Cmd/Ctrl + Alt + V` or `Alt + Click` on the Paste button

Changes are applied immediately.

Right-click a grading point to access **Copy rule**, **Paste rule**, **Paste X only**, and **Paste Y only**, as well as **Grade proportionally** and **Set rule to 0,0**. Actions are enabled according to the current selection and available rules. When rules have been copied and the current selection supports pasting, you can also open this menu in the Grade Rule panel outside its input fields. Right-clicking empty preview space opens the general preview menu instead.

***

### Directional grading (advanced)

Directional grading lets you edit dx/dy along rotated local axes.

* Activate from the Grade Rule panel header button or press `D` to cycle through:
  * Previous
  * Next
  * Tangent
* The preview shows a visual direction hint.
* Press `Esc` to exit directional mode.

***

### Proportional grading

#### 1. Auto-Interpolation (Single Point)

Location: Grade Rule panel on the left

**Steps**

1. Select the relevant point
2. Click the Route icon at the bottom of the panel, or press Alt + P

The point will be automatically interpolated based on the previous and next points along the contour.

#### 2. Auto-interpolation (all point on a segment)

Location: The right sidebar of the preview:

**Steps**

* Activate with the "Route" icon or `Alt + Y`.
* Select:
  1. A start point
  2. An end point on the same piece

Grading rules are interpolated along the shortest contour path and applied to all encountered points.

* Hold `X` or `Y` to force an axis
* `Alt + X` resets the start point
* `Esc` exits the tool

#### 3. Proportionally (based on start and end points)

Location: Right sidebar of the preview:

**Steps**

1. Activate the tool using the Route icon or Alt + Y
2. Select a start point
3. While holding Shift, click an end point on the same piece
4. Select one or more target points

The grading rules will be applied proportionally to all selected target points.

***

### Grading links (advanced)

Grading Links synchronize grading rules between pieces with matching internal points.

**Steps**

1. Select multiple points on the same piece.
2. Activate **Link pieces** (`Alt + L`).
3. Click the target piece in the preview.

Points are matched by name.

Links can be managed in **Grading Links**:

* Enable / disable
* Show linked points
* Delete links

***

### Grade to Boundary

Use **Grade to Boundary** to apply grading to an internal-line endpoint using a target boundary segment.

1. Activate Grading mode and select **Grade to Boundary** in the preview toolbar.
2. Select an internal-line endpoint.
3. Select the target boundary segment, following the hint bar.
4. Review the resulting grading in the preview.

Press **Esc** to exit the tool.

***

### Navigation While Grading

While Grading mode is active, you can:

* Pan the pattern using Space + drag
* Zoom in and out using the mouse wheel

This helps improve precision when working on dense or highly detailed areas.

***

### Rotate and arrange pieces while grading

Use the same [alignment and placement controls](/manage-a-project/preview-tools.md#select-and-rotate-pieces) as in the normal preview:

* **Align…** in the piece context menu aligns two selected points horizontally. You can also click a yellow highlighted contour or internal-line segment to use its endpoints.
* **Shift + click** on a piece's body adds or removes it from the piece selection. With a piece selected, **Ctrl/Cmd + A** selects all visible pieces.
* **R** rotates all selected pieces clockwise by 90°, each around its own center. Without a piece selection, it rotates the piece under the pointer.
* **Ctrl/Cmd + Alt + X** spaces out all visible pieces, including the geometry of the sizes currently displayed, while keeping their rotations and flips.
* **Ctrl/Cmd + X** with the pointer over a piece restores that piece's original position and orientation. **Alt + X** restores all pieces when no grading tool uses that shortcut.

Selecting pieces is separate from selecting grading points. **Shift + click** on a grading point keeps its existing selection behavior.

Click empty preview space or press **Esc** to deselect pieces without leaving Grading mode. **Esc** exits an active tool first. If grading points are also selected, the first **Esc** clears the pieces; a further **Esc** clears the grading points.

***

### Exporting grading data

When generating the .dxf pattern file:

* Enable **Enable grading** to include the `.rul` file in the download.
* A Size Chart must be assigned and a plan with `grading pack` is required.

***

{% hint style="info" %}

#### Important

If a **Size Chart Template** is assigned directly to a pattern, any changes made to the template will be applied to all patterns that use it.

If, instead, the template was assigned as a Local Copy, changes made to the original template will not be propagated to those patterns.

Before editing a Size Chart Template, always check how it has been assigned to avoid unintended changes across multiple patterns.
{% endhint %}