FLUX Klein adds red-box placement for interior object edits

• A Stable Diffusion workflow thread showed a familiar failure mode for interior edits: FLUX.1 Fill dev and SDXL inpainting can add objects, but placement drifts when the only control is a painted mask.
• According to a near-identical follow-up, users are getting tighter placement from FLUX Klein by drawing a red rectangle or dot directly on the image, then prompting the model to place the object there and remove the marker.
• A ComfyUI thread mapped a different layout-first pipeline for sketch-to-photo edits: turn the sketch into a scene description, use ControlNet on the sketch, then do the face swap after the scene is locked.
• One AI art post is a reminder that even when the tool works, style fusion still takes repeated passes. Its creator said a fluffy 3D character blended into a Renaissance painting took "quite a few tries."

Black Forest Labs' FLUX.1 Tools post introduced Fill as a mask-based inpainting and outpainting model, while the official inference docs and model card frame it the same way. The interesting part in today's community threads is the workaround layer on top: red boxes, red dots, pasted-object LoRAs, and ControlNet Union suggestions in the comments to force layout before the fine details.

The original post tried three routes for home-interior object insertion: FLUX-2-Klein-9B, FLUX.1-Fill-dev, and SDXL inpainting. The complaint was specific. Klein often produced a plausible object, but not in a controllable location, while Fill and SDXL gave weak edits even with a user-painted mask.

The useful comment pattern across the first thread and the follow-up was simple:

• draw a solid red rectangle where the object should go
• or mark the position with a red dot
• prompt for the object inside that marker
• explicitly tell the model to remove the marker afterward
• if needed, paste the object into the target area first and use a Flux Klein LoRA or edit model to harmonize it

That is more concrete than plain masking, and a lot closer to art direction than hoping an inpaint model reads intent from a blank region.

The ComfyUI comments sketched a separate recipe for people trying to merge a hand-drawn scene with a real person's face. The proposed order matters:

1. turn the sketch into a richer scene description with an LLM
2. run the sketch through ControlNet, using canny or depth, to keep composition
3. generate the photoreal base image first
4. extract and upres the face region
5. swap in the real face with ReActor
6. downscale and composite the swapped face back into the scene

The thread's most useful distinction was that identity comes after layout. The scene has to land before the face swap has any chance of looking intentional.

The same day also produced a smaller but very familiar datapoint from the creator side. An aiArt post said a fluffy 3D character pushed into a Renaissance painting with ChatGPT Image took multiple attempts to get the texture and painting style to blend cleanly. In the comments, the creator added that they had already animated the character too.

That detail lands because it matches the workflow threads above. Whether the job is interiors, face edits, or style transfer, the clean result usually comes from staged control, then iteration.