Designing the inscription on the image in Photoshop

Create a style of inscription on the image. This inscription (Texto oculto) will be present on all images of the site. The inscription should be unobtrusive, not interfere with the review of the image itself and at the same time, reliably protect it from unauthorized copying and further use.
The inscription should be in harmony with the design of the site or be neutral. The design wishes are elegant, unobtrusive, perhaps semi-transparent.

From you, with a satisfactory result - transfer to the customer the font file (for the Photoshop program) and help in setting up, so that in the future it can be used independently.
The subject of the site is the sale of medicinal herbs, herbal fees, medicinal berries and roots.