diff --git a/.env.example b/.env.example
index 57226c9..24b5bd1 100644
--- a/.env.example
+++ b/.env.example
@@ -16,8 +16,10 @@ COMFYUI_PORT=8188
 # Key: DON'T use --gpu-only - it fights the unified memory fabric
 # --disable-pinned-memory: reduces overhead on unified fabric
 # --force-fp16 + --fp16-*: enables SageAttention optimization
+# --fp32-vae: run the VAE in fp32 - fp16 VAE produces NaNs -> BLACK images on
+#   many SD1.5/SDXL checkpoints. (Use --bf16-vae instead for a faster compromise.)
 # --dont-upcast-attention: keeps attention in FP16 for speed
-COMFYUI_FLAGS=--listen 0.0.0.0 --port 8188 --disable-pinned-memory --force-fp16 --fp16-unet --fp16-vae --fp16-text-enc --dont-upcast-attention
+COMFYUI_FLAGS=--listen 0.0.0.0 --port 8188 --disable-pinned-memory --force-fp16 --fp16-unet --fp32-vae --fp16-text-enc --dont-upcast-attention
 
 # Build refs (pin to specific commits/tags for reproducibility)
 COMFYUI_REF=master
diff --git a/README.md b/README.md
index da69b81..a5d0ec6 100644
--- a/README.md
+++ b/README.md
@@ -40,10 +40,15 @@ The DGX Spark's Grace-Blackwell architecture uses **unified memory** - a coheren
 ```bash
 --disable-pinned-memory   # Reduces overhead on unified fabric
 --force-fp16              # Enables SageAttention optimization
---fp16-unet --fp16-vae --fp16-text-enc  # FP16 precision throughout
+--fp16-unet --fp16-text-enc  # FP16 precision for UNet + text encoder
+--fp32-vae               # VAE in fp32 - fp16 VAE causes NaNs -> BLACK images
 --dont-upcast-attention   # Keeps attention in FP16 for speed
 ```
 
+> **Black/blank images?** That's the classic fp16-VAE NaN issue, not an NSFW
+> filter (there is none). Keep `--fp32-vae` (default). `--bf16-vae` is a faster
+> alternative that also avoids the NaNs.
+
 **What NOT to use:**
 - `--gpu-only` - fights the unified memory fabric, hurts performance
 - `--cache-none` - disables natural caching, slows model loading