Picture Merge is a simple tool that allows you to merge any picture into another, for an artistic effect or an image watermark.

 

Just choose an overlay file, and it will display a preview for the first image in your current list.

You can choose the transparency level, and also if the merge will apply for the thumbnail, the overlay or both.

 

If you only need the effect applied to a single item, you might want to use the Picture Merge tool.