Watermark (static image overlay) in a CMS lightbox

Hi, my client wants to have a watermark over CMS images, his old website could add it automatically. So instead of that, I placed a PNG over the gallery thumbnails. But is there a way to replicate this in an open lightbox? Something like an overlay taking 60 % of the width of the original image.

I know this is a workaround but combined with disabling right-click on the page it’s all I can think of.

Or is there a way to add a proper watermark to the original images? I have found a script that can fetch the CMS image URL and another one for combining two images, could this work on Webflow or would the CDN prevent manipulating the original image?


Here is my site Read-Only: Webflow - Hanousek a partneři