What a clipping mask has to keep when you save a vector document

Draw a colored rectangle and place a smaller ellipse over it in the same layer and group. Select both and choose Object → Make Clipping Mask. The ellipse defines the visible area. The parts of the rectangle beyond it should reappear when you release the mask.

Save the native .vector.json document and reopen it. Select the clipping group and choose Object → Release Clipping Mask. Then undo the release. The same sequence works with an embedded image under a closed path. The two sample files start with their clipping groups already in place.

When you make the mask, Si takes the top selected item as the boundary and stores it as the first child of a clip object. Each child carries its own data. In the raster sample, the second child retains the embedded JPEG, its dimensions, and its transform.

The file loader checks that a clipping group has at least two children and that the first child is a closed path or compound path. The renderer rebuilds a Paper.js group and enables clipping on it. Release disables clipping and moves the children out of the group as separate objects.

item = new e.p.Group({
  children: o.children!.map(child => restoreItem(e, child)),
  insert: false,
});
if (o.objectType === 'clip') {
  item.firstChild.clipMask = true;
  item.clipped = true;
}

The earlier browser suite created both masks through Si’s editor controls. It also moved the vector group and checked that Undo and Redo restored its object data. For this article, we started a fresh local Edge session for each saved fixture and repeated the save, open, release, and Undo sequence.

Both saved files matched the editor snapshot. After reopening, the document matched that snapshot apart from the new document ID. Releasing each mask returned two objects and preserved the original artwork record. Undo restored the reopened group and its child data.