⚗ Alchemica · Save Image (cartella) [1.0, use Alchemica Save Image (pick the folder)]

portraits/run_a/2026/client_preview is a lovely filename prefix right up until you typo it and ComfyUI makes a brand new folder in silence. This node replaces the typing with a dropdown.

What it is

AlchemicaSalvaImmagine is the AlchemicaSampler pack's save node: same PNG, same embedded metadata as ComfyUI's own Save Image, but instead of typing a subfolder into filename_prefix you pick it from a menu. It's the original 1.0 version, Italian widgets, and it now shows as "⚗ Alchemica · Save Image (cartella) [1.0, use Alchemica Save Image (pick the folder)]" in the pack's legacy category.

There's a short family tree here worth knowing, because the pack shipped three of these. This one came first, with a cartella dropdown built by listing the subfolders of ComfyUI's output folder at startup. The English restyle made it AlchemicaSaveImage (images, folder, new_folder, filename_prefix) - same code, standard names. Then the changelog admits the dropdown's flaw and AlchemicaSaveImagePath replaced that: a folder list built at startup "looked random" as your output folder grew, and it failed validation when a folder saved in a workflow no longer existed.

If you're building a graph today, use ⚗ Alchemica Save Image (drive + folder + workflow name). This node is for the workflows already pointing at it.

Inputs and outputs

• images - what you're saving. Batch goes in as-is.
• cartella - a dropdown of folders inside ComfyUI's output directory, plus (radice output) for no subfolder and (nuova cartella) for a new one.
• nuova_cartella - the name for the new folder. Only read when cartella is set to (nuova cartella); leave it empty any other time.
• filename_prefix - the base name, defaulting to immagine. Files come out numbered immagine_00001_.png and so on.

No outputs. It's a terminal node, like Save Image itself.

Two behaviours worth knowing. It writes the same PNG metadata as ComfyUI's Save Image, so dragging the saved PNG back onto the canvas restores the workflow - that convention is the only reason PNG beats WebP as an output format, and it dies the moment anything re-encodes the file. And it declares validation as always-true, which is the fix for the old failure: a workflow saved with a folder that no longer exists now runs instead of refusing to queue, and the folder is created again at save time.

Installing it

ComfyUI Manager, search "AlchemicaSampler", or:

cd ComfyUI/custom_nodes
git clone https://github.com/Nessuno76/ComfyUI-AlchemicaSampler
# restart the ComfyUI server - a page reload won't register new nodes

No Python dependencies beyond ComfyUI (the pack lists none at all), and the node itself doesn't care which model you're running. The pack wants ComfyUI 0.36.0+, but a save node isn't where that bites.

Where it goes wrong

• The folder you want isn't in the list. The menu is built when the server starts. Create the folder, then restart.
• It saved somewhere unexpected. filename_prefix with a slash in it still creates subfolders, the way core Save Image does - the dropdown doesn't disable that habit.
• (nuova cartella) with an empty name. It raises rather than guessing. Pick a name or pick an existing folder.
• You want it on a different drive. This node can't. It only writes inside ComfyUI's output directory - that's precisely the limitation AlchemicaSaveImagePath was built to remove.