I'm sure there is a simple way to put in a background layer, but I'm not finding it. Here's what I'm trying to do. I have drawn an image with lots of detail, but on a white background. Now I want to create houses to go behind what I've already drawn. If I create a new layer for the houses, and move the layer below the main drawing on the layer stack, it doesn't appear at all. I don't want to change to opacity of the main layer. I've tried experimenting with masks and filters, but to no avail.

How do I make the house layer appear behind the main drawing, where it is properly occluded so it only shows where the main drawing allows it to?

Thanks!

Gary

You'll have to remove the white first to make that layer have transparent pixels. There are lots of different ways of doing that, one of them is to use the Similar Color Selection tool.

Thanks for your quick reply. Once I use the "magic wand" Continuous Selection Tool, how do I remove the white that has been selected? And I have many layers on the main drawing that I am trying to make a background for. Which layer do I select to find and remove the white?

Gary

When a region has been selected, by any method, you can press the Delete key to clear all the pixels in the region.
After using the Similar Colour Selection tool to select the region then after clearing you may find that a small number of 'white' pixels are left behind on the edges of your drawing. These are probably pale grey pixels (or similar pale colour) depending on the characteristics of the edges of your drawing lines. You can get rid of these by redoing the process with a higher Fuzziness setting (in the Tool Option docker) before you use the selection tool.

If you have many layers of this nature, you'll have to do the process on each one in turn. In case of complication or confusion, you can hover your cursor over a layer in the Layers docker to see an enlarged thumbnail picture of the layer contents. If you want to be totally certain, you can turn off the visibility of all layers and then select and turn them on one at a time to see them and operate on them.

This is a good illustration of the principle that 'different things should go on different layers' so that you can keep them separate for future modification.

Perfect, I'm getting the results I wanted - thanks