Blend Modes? This blows my mind! There's a lot iCalamus can do - Is this something like ·Blind Modes·?
No, keep cool. iCalamus supports all blend modes as supported by the PDF specification. This means you can define by a mouse click how two frames should be blended. Date structures keep totally untouched. You can't damage anything.
Think about printing a document area in inversed colors, creating color shifts or filter effects or simply fade out areas temporarily without having to erase or move frames.
Gives you the fastest possible results without a high learning curve in image editing.