Layer Order

Z-order is half of compositing, and most of the time you don't discover you got it wrong until the render is done. Layer Order is the fix-without-rebuilding node: it moves one layer through the stack - front, back, one step either way, or to an exact slot - or sorts the whole stack by name or by the area each layer covers. Hand it the LAYERS document, and it hands back the same document renumbered from 0 at the bottom.

How to drive it

You target the layer with index (0 = bottom of the stack, -1 = front, negative counts down from the top) or layer_name. The move dropdown does the actual work:

• to front / to back - one layer over or under everything.
• up one / down one - swap with its neighbour, which is the polite way to nudge a layer past another without guessing positions.
• to index - drop it at target, counting the same way.
• The sort moves - by name A→Z or Z→A, or by area small→large or large→small - reorder every layer, not just the one you picked.

A nice detail: index and layer_name are ignored by the sort moves, so you don't need to clear one to use the other. Name matching is case-insensitive, and the layer lookup is fuzzy on the back end - ask for 'sky' and it finds 'Sky Backdrop' if nothing is called exactly Sky.

Outputs you'll actually use

The layers output is the reordered stack, numbered from 0 at the back with no gaps, ready for Create Layered Image or another edit. The index output tells you where the moved layer landed - useful when you're building logic that needs to remember "the plate is now layer 2" for a later edit. After a sort that had nothing to follow, it reports -1, which is its way of saying the move didn't apply.

One genuinely useful pattern: combine a sort by area, largest first, with Layer Select or Layer Remove. Sort the stack so the big background layers sit at the bottom, then drop everything above a threshold - you've just turned "clean up this document" into one deterministic pass instead of a pile of index arithmetic.

Installing it

Layer Order is one node in WAS Node Suite, so install the pack once:

cd ComfyUI/custom_nodes
git clone https://github.com/WASasquatch/was-node-suite-comfyui.git

or search "WAS Node Suite v3" in ComfyUI Manager and restart. It needs ComfyUI 0.14.0+ and Python 3.10+. The pack installs no pip packages in v3 - if an old guide tells you to pip its requirements.txt, it's talking about the v2 era and you can skip it.

Where people trip

The off-by-one trap is the recurring one: this pack numbers 0 from the bottom, so "the last layer" is -1, not a high positive number. If you move to an index past the end, the node treats it as a miss rather than clamping silently - you'll see a clear error naming what the stack holds, which is better than a mysteriously wrong render. And remember the sort moves renumber everything, so any later node addressing a layer by index needs to re-read where things landed (that's what the index output is for). If you address by name instead, reordering never breaks your wiring.