How To Add A Watermark File To MyPhotoApp.
Automatic watermarking of gallery images when you upload is available in the professional subscription level of MyPhotoApp.
To add watermarks to your images, you first need to to go the setup tab to upload a watermark png file that will be used on your gallery images.
Once you upload your png file, you will have an option on the gallery section on the builder tab to select the placement of where you want to place the watermark. Any images uploaded to that gallery will have the watermark applied to the location you specified.
NOTE: Watermarking is applied to images on upload. Only images uploaded to your gallery after you have turned watermarking on will have the watermark applied. Existing images in the gallery prior to watermarking turned on, will not have the watermark applied.
If you do not want a watermark applied, you can turn it off by selecting a placement location of None.
How To Create A Watermark PNG file.
A watermark file is a png file that has a transparent background. The size of the file needs to be congruent with the size of the photo files you will be uploading into the gallery. The watermark will be used as is, unless it is larger than the photo file being uploaded in which case it will be resized to fit on the photo file.
Attached is an example watermark file graciously provided by Bill Tucker. You can download it and take a look at it in Photoshop if you want to get an idea of what a working watermark file looks like.