Image Grain Add

Modern base models, Flux especially, have a signature "plastic" look - skin like a mannequin, surfaces that are too clean, a general airbrushed sheen. One of the cheapest fixes is the oldest photography trick there is: add grain. A little noise texture over the top and the eye reads the image as a photograph instead of a render. This node does that in one step, with one dial.

RES4LYF's author has been chasing the anti-plastic problem for a while - the repo even ships an "amateur cell phone photo" LoRA specifically to fight Flux's blurred, plastic default. This node is the post-process end of the same fight: rather than change how the image is generated, it roughens the finished pixels so they stop looking synthetic.

How it works

It overlays a grain pattern onto the image and blends it in by weight. Low weight is a subtle tooth that just takes the digital edge off; high weight is visible, gritty film grain. It's a final-stage cosmetic pass - run it after your VAE decode, near the end of the graph, right before you save.

The inputs that matter

There are two:

• image (IMAGE) - the finished picture you want to rough up.
• weight (FLOAT, default 0.5) - how much grain. Around 0.5 is a sensible, believable amount for most photoreal work. Drop toward 0.1–0.2 if you just want to break the plastic sheen without anyone noticing grain; push higher for an overt analog-film feel. Past a point it reads as noise rather than grain, so nudge it and preview.

The single output is IMAGE.

Installing it

ComfyUI Manager: search RES4LYF, install, restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/ClownsharkBatwing/RES4LYF/
cd RES4LYF
pip install -r requirements.txt

pip install in the venv or portable Python, restart, hard-refresh (F5). Nothing to download.

Where people get tripped up

Order matters. Grain is a finishing move - add it after upscaling and any other post, not before. If you grain and then upscale, the upscaler will smear or resample the grain into something muddy, and you've lost the crisp texture that made it work.

The other trap is overdoing it and calling it realism. Grain hides a plastic surface; it doesn't fix bad lighting or a flat composition. If the underlying image looks synthetic for structural reasons, grain just gives you a grainy synthetic image. Treat it as seasoning on an already-decent render, and keep the weight lower than you think you need - believable grain is usually the amount you can barely see.