Blend

Blending two images is a bread-and-butter compositing move: a watermark, a texture overlay, fading a second reference into your shot, ghosting a guide image on top of a render. Stock ComfyUI leaves you to hunt for the right math node; LF_Blend gives you image, overlay_image, and an opacity slider, and composites the second onto the first. That's the whole node - and for the LF Nodes family, that's the point.

The "and actually see it happen" part is the differentiator. It ships with a KUL_COMPARE widget, the before/after style used across this pack's filter nodes, so the blend is rendered and inspectable right on the node body. You slide opacity and see the result instead of queueing, squinting at a preview, and re-queueing.

The inputs that matter

• image - the base image.
• overlay_image - drawn on top.
• opacity - 0 to 1, default 0.5. 0 means the overlay is invisible, 1 means it completely replaces the base. Defaults to the middle, which is the right instinct for most soft-overlay uses.

It outputs image (the composited batch) and image_list. Both are pass-through friendly - feed the result on into a save node or further processing. Like the rest of this pack's filter nodes, it handles batches, so a list of bases and overlays get blended pairwise.

A word of caution on the name

"Blend" here is a simple alpha mix at an opacity level, not a Photoshop-style blend-mode menu. There's no multiply, screen, or overlay blend mode - if that's what you need, look at other packs' image blend nodes or a math node. Where LF_Blend wins is speed and simplicity: the two images plus a slider case, done well.

Installing it

Standard LF Nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/lucafoscili/comfyui-lf

or ComfyUI Manager → LF Nodes → install → restart. No dependencies, no models. The pack is the legacy, frozen repo (development moved to lf-nodes), so this node is stable, finished, and unlikely to gain blend modes.

Where people get burned

• Image size mismatches. If image and overlay_image have different dimensions, the node does no auto-resizing - you get an error or a silent mismatch depending on the version. Resize or crop the overlay to match the base first.
• Alpha handling: a PNG overlay with transparency behaves as you'd expect only if the pipeline preserves the alpha channel through to this node. If your overlay arrives flattened to black, that's a chain problem, not a node problem.
• opacity at 1.0 is not "additive" - it's replacement. If you want a mix that keeps highlights from both images, this isn't that.

For quick, visual compositing inside the graph, this is one of the friendlier entries in the LF filters family.