Skimmed CFG - Timed flip

The SkimFlipPreCFG node is the "Timed flip" entry in Extraltodeus's Skimmed_CFG pack, and it has a different personality from its siblings. Where the others are anti-burn dials, this one is an enhancer: it flips the skimming filter at a chosen point in the denoising process, and that mid-course change is what makes SDE samplers react extremely well. If you've written off stochastic samplers because they burn or get chaotic, this is the pack's answer.

How it works

Under the hood it's the main skim node configured for a full skim of the negative, with the fallback following the sampler's current CFG scale, plus one extra move: at flip_at, the flipping filter flips. Before the flip the standard three-condition filter governs which latent values get skimmed; after it, the broader mask (what you'd get with the "disable flipping filter" flag) takes over. The sudden change in how aggressively the skim acts is what produces the extra randomness and quality. It's built for normal CFG scales, so think of it as a quality/character enhancer rather than a burn emergency tool.

The flip_at tooltip tells you exactly how to aim it: fully at 0 gives smoother results, fully at 1 gives noisier results, and the influence is concentrated in the first 0–30%. Default is 0.3. The reverse toggle flips the other direction and lands you closer to an unmodified composition.

The inputs

• model - MODEL in from the loader.
• flip_at (default 0.3, 0–1) - where in the step progression the filter flips. Lower = smoother, higher = noisier; most of the effect lives in the first 30%.
• reverse (default off) - invert the flip for output closer to no modification.

Output: a patched MODEL. SDE samplers are the target; standard samplers also respond.

Install

Part of Extraltodeus/Skimmed_CFG - one Python file, zero pip deps, no model downloads. ComfyUI Manager: search "Skimmed_CFG" (Extraltodeus), install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/Extraltodeus/Skimmed_CFG

Restart after either.

Caveats

• Inert at CFG 1 - no unconditioned pass, no filter to flip. SD/SDXL-lineage at normal CFG is the intended regime.
• Rename note: current name for what used to be "Skimmed CFG - Timed flip"; old workflows using that name can flag missing after the January 2026 rename - this node is the same behavior.

If you're on an SDE sampler and the output feels either burned or flat, set flip_at around 0.2–0.3 and see what happens. It's the one node in this pack people describe as fun.