How would I go about making a simple, tiling texture with Acorn for Mac? Is there a tool, or a function or something I can't find, or can it not be done with such a simple application? If you know of a way to do this in Photoshop, there's a good chance it will work in Acorn.
Start with a square of document, make a texture.
Make a new document the same size.
Make a square selection exactly 1/2 the size of the square in each dimension (so 1/4 square).
Copy the upper left quadrant and paste it into the new document, placing it as the lower right quadrant.
Copy upper right quadrant and paste it into the new document, placing it as the lower left quadrant.
Repeat with the two remaining quadrants.
You now have the same texture, with the outer edges as the center lines of the document.
fudge the edges until the center lines blend.
In Photoshop, there is a filter/tool called "offset" which will swap the quadrants for you.
Test the tile by exporting it and using a simple html page with the texture name as a repeating background.
There are many tutorials for how to do this on the web.
Here's a good one straight to the point.