Before version 11, small product icons displayed on the city map were scaled down in-game using a simple algorithm, which caused the visual jarring. To improve this, we include a batch file called make_small_images.BAT in the MOD kit for version 11.0, located in the \MOD_kit\Images\Products folder. This file allows you to batch produce small images based on the standard images.
Here's what the make_small_images.BAT file looks like:
rem make smaller versions of the product images and save them in \small
rem smaller versions of the product images are displayed in various places in the game. For example, factories in the Firm Summary report showing the products they produce
rem you can download the magick app that this batch file runs from https://www.imagemagick.org/
md small
del small\*.png
magick mogrify -format png -define png:color-type=2 -resize 40x40! -path small *.png
cd small
pack
cd..
You would need to download and install the magick app from https://www.imagemagick.org/ first in order to run this batch file.
This screen shows the improved image quality of the small product icons: