Why do my 'small' images appear poor quality and of low resolution when they aren't

Question

I am trying to figure out the optimal size for the 'small' images (the one that will appear on a category page) but no matter what size or resolution I make them, they appear as low resolution - I have tried them from as high as 2000 x 2000 px - down to 250 x 250 px and they are always saved as optimized for web through Photoshop

Answer 1

All images in the frontend are automatically resized based on theme settings. The sizes are defined in etc/view.xml of the theme and are different for various areas, like the category grid.

For example: luma/etc/view.xml

<image id="category_page_grid-1" type="small_image">
    <width>240</width>
    <height>300</height>
</image>