How would I blend two versions of a graphic like this?

[mattc45205971]

hello! I am working on my website to sell my children's book and I have an original version of the story and a coloring book version. How would I go about combining these two exact same versions down the purple line for example. Sorry for the crude example from my phone. I want to use one image to convey both versions of products with the top left being the normal as seen below and the bottom right half my simple black & white coloring version. All alignments are the same so in theory it should be seamless if I do it right, I just don't know how! Thank you!

 

[Conrad C · Accepted solution]

If I understand correctly, I would do it with these steps, as shown in the demo below:

1. Have both versions on their own layers in the same document.

2. Draw a triangle path (not shape layer). I did it by starting with a rectangle drawn using the Rectangle tool (not Rectangle Marquee) set to Path mode, then I used the Pen tool to delete one corner point so that what’s left is a perfect triangle.

3. With that path selected in the Paths panel, I chose Layer > Vector Mask > Current Path. That command uses the selected path to create a vector mask to hide the half of the selected layer. 

I like this method because as a vector path, as you can see near the end it’s a nice hard edge that is easy to adjust at any time, using the path editing tools.

[mattc45205971]

@Conrad C Thank you so much! This is perfect! As a follow up now that I have this basic premise down thanks to you, is there a tool that I can use to "brush" the dividing line and make it a softer transition between the two? With a kids book theme, I'm going for something for soft and whimsical rather than perfectly straight. Thank you SO MUCH for taking a moment to help me out!!

[Conrad C · Accepted solution]

This is another reason I like vector masks: Easy feathering. Steps for the demo below:

1. Select the vector mask. This causes the Properties panel to display vector mask properties.

2. In the Properties panel, adjust the Feather option. However, this causes a problem in that the left and bottom edge are also feathered, because it feathers all edges uniformly. So…

3. With the vector mask path selected in the Paths panel, choose Edit > Free Transform Path, and scale it up to get the left and bottom edges away from the canvas edge to hide the feathering along those edges. 

Now, because you mentioned wanting a whimsical children’s look, maybe what I have suggested so far is not the best solution. Instead, you might consider painting a pixel layer mask with an expressive brush preset so that you can create any kind of non-regular mask edge you want, as shown in the demo below.

[mattc45205971 · Accepted solution]

Amazing. Thank you again @Conrad C !