How to make an image grid
Grid is an image, composed of multiple images. You can add text overlays with information about each picture like its seed, prompt etc. It's a great way to compare different parameters.
First you need to download and install ImageMagick, a free image-editing library: https://imagemagick.org/script/download.php
Append your network with a WaitForAll node. It will wait for all the tasks to complete and gather them into one task. After it put an ImageMagick node. Set the output directory and cook the node, you'll get a simple grid of all your incoming images.
If you want to add text overlay, append an SD Png Info node before the WaitForAll node. It will create attributes for all the generation parameters. In the WaitForAll node change Apply operation to "Append to array".
In the ImageMagick node select:
Overlay: Attribute array
Attribute array name: any attribute, for example seed.
Extra arguments (Custom Value):
fill - white (font color)
pointsize - 40 (font size).
Cook node and you'll get captions under each image.
Note that you need to manually delete the resulting image before recook. Right-click on the node, choose "Delete this node's output files...".
You can add more Extra arguments for more precise control over the result, see the ImageMagick documentation.