Using Paint.Net Alpha Paste plugin to create a shadow

Paul Sweeney · 17th January 2021

paint.net

An short walkthrough of creating a shadow using the BoltBain alpha paste plugin for Paint.Net…

Alpha Paste plugin install

To add the Alpha Paste plugin to the free windows image manipulation program Paint.Net:

  • download BoltBait’s plugin pack.
  • unzip the file and run the .exe inside
  • exit any running Paint.Net
  • agree to the T’s & C’s then click Install everything! (or choose less if desried)

Using the Alpha Paste plugin

I want to change the following shadow image I saw in an email …

Grey shadow

… into a blue-ish version for use in my website.

I’ve got this in just a few simple steps:

  • load the shadow up in Paint.Net
  • add a new layer
  • fill the new layer with the solid blue colour (use rectangle tool)
  • select the existing shadow layer image, and copy the whole image (ctrl-a ctrl-c).
  • select the blue layer and choose Effects -> Object -> Paste Alpha...
  • make sure Replace current alpha with... and Shades of grey on clipboard... are selected and Invert calculation is checked
  • click OK
  • select the orginal shadow layer, and fill it with white
  • save the image as a png (accept the warning that the layers will be “flattened”).
  • flip vertically and save again.

The up and down image versions can now be used :

up shadow

This is the message which I want to draw attention to, but not too much!

down shadow

That was easy, and looks pretty sweet I think.