Making 'white' area in a bitmap transparent.

[iMatt]

As the title suggests, I have a large collection of ornate TIFF images. They are designed to create even more ornate patterns when overlayed. naturally, this requires transparency set to 0% so that the overlay works. How do I set transparency in Aff Designer so that each image shows below the one placed above (or below)? As you can see the image above is covered by the 'white space' of the lower image.

[Alfred]

Go to the Layers panel and click on the upper layer to select it. Now click on the ‘Blend Ranges’ gearwheel at the top of the panel to display the Blend Options dialog.

At the top of the Source Layer Ranges graph you’ll see a line joining a black node on the left to a white node on the right. It’s at the top of the graph because everything is at 100% opacity, but if you drag the right-hand end all the way down you’ll make the white pixels in your image 0% opaque (i.e. 100% transparent). At this point the black pixels will still be 100% opaque but everything else will be semitransparent; to restore full opacity to all the non-white pixels, drag the left-hand end of the line straight across towards the right, stopping when the white pixels begin to reappear.

[gdenby]

Dang, I always forget about blend ranges. Don't know why. Just tried that on some line art, and found that adding another node at 5h 50% position sitting at 100% cleaned up the line art.

[lepr]

.

[Fixx]

11 hours ago, gdenby said:

Dang, I always forget about blend ranges. Don't know why.

Because they are not so readily available as in Photoshop..

[iMatt]

15 hours ago, αℓƒяє∂ said:

Go to the Layers panel and click on the upper layer to select it. Now click on the ‘Blend Ranges’ gearwheel at the top of the panel to display the Blend Options dialog.

At the top of the Source Layer Ranges graph you’ll see a line joining a black node on the left to a white node on the right. It’s at the top of the graph because everything is at 100% opacity, but if you drag the right-hand end all the way down you’ll make the white pixels in your image 0% opaque (i.e. 100% transparent). At this point the black pixels will still be 100% opaque but everything else will be semitransparent; to restore full opacity to all the non-white pixels, drag the left-hand end of the line straight across towards the right, stopping when the white pixels begin to reappear.

Thanks a LOT for this!!! It works brilliantly! My problem is I am still a bit too used to the way CorelDraw does things. Or rather DID as I am now using Affinity Designer, Photo and soon Publisher full time.

[Patrick Bell]

and for me too. Thanks

[jmigues]

  Thank you this is exactly what I was looking for. 

[ESPR]

Alternative solution:

If you have black on white (lineart being the classic example), the Blend Mode 'Multiply' will make the white transparent.

If its white on black, 'Screen' will make the black transparent.

[Alfred]

29 minutes ago, ESPR said:

Alternative solution:

If you have black on white (lineart being the classic example), the Blend Mode 'Multiply' will make the white transparent.

If its white on black, 'Screen' will make the black transparent.

The ‘Multiply’ (or ‘Screen’) blend mode will make the white (or black) behave as though it’s transparent, letting the colour show through from the layers below, but if you export the result to PNG and then open the exported file you’ll find that the white (or black) areas — instead of showing up as a transparency chequerboard — are unchanged.

[ESPR]

11 minutes ago, Alfred said:

The ‘Multiply’ (or ‘Screen’) blend mode will make the white (or black) behave as though it’s transparent, letting the colour show through from the layers below, but if you export the result to PNG and then open the exported file you’ll find that the white (or black) areas — instead of showing up as a transparency chequerboard — are unchanged.

The original poster said he/she wants to stack/overlay a bunch of ornate layers, so each layer adds to the final design.

It says nothing about exporting with a transparent BG, but i guess, looking at the title it could be read both ways.

 

The Blend Mode method makes the white transparent in the project, which is what OP wanted.

Your Blend Ranges method is superior because it also exports as transparent.