The ideal file size is between 900×900 and 1800×1800
The type of images that work best are either busy rich images where everything is in focus, or images that have coloured backgrounds with a gradient fill
Apply any textual elements after watermarking the image, taking care not to obscure too much of the image.
If you watermark an image with text in, the text can appear ‘jagged’
Avoid images with blurred elements. Blurred elements in images (e.g. blurred backgrounds) can end up ‘jagged’ and pixellated.
Avoid images with too much white. White areas cannot be watermarked, and areas bordering the white will look ‘jagged’.