The third type of Mosaic crochet is not as commonly used. It involves a type of spike stitch, and can be reversible. It is a bit more involved then the previous methods, but with stunning results.
The most famous patterns using this approach are in the book and video by Lily Chin, Mosaic Magic.
This method uses 2 rows of each color. Allowing for carrying the color changes up the side like Inset Mosaic, and not weaving in ends like that of Overlay Mosaic Crochet.
How to work the stitch- Mosaic Magic
Using Long Loop Double crochet, essentially working a regular double crochet, but the insertion is 2 rows below the working row. The “anchoring” loop is pulled up to the height of the fabric, as a long loop. Work this as such: Yarn over, insert hook into indicated stitch 2 rows below working row, yarn over, pull through a loop, pull up to height of fabric, and finish the double crochet.
A double crochet long loop, or double crochet spike or flame stitch is worked instead of a single crochet because it allows for a bit more fabric at the top of the stitch. A single crochet would create more gapping, or holes in the fabric.
One thing to consider with Mosaic Magic is that the “spike”, “long loop” or “flame” is not very wide. As such working 2 of these stitches next to each other does not create a flattering look. It doesn’t look completed, and a bit amateurish. To compensate for this, look for patterns that only have 1 drop down stitch in a sequence.
Another benefit to this approach is that you can work stitches diagonally by simply not working in the stitch directly below. This can create some hounds tooth effects. Crossing the “spike” stitches can create rounded effects.
I would recommend that you give this or any of the 3 methods for Mosaic Crochet. Check out Lily Chin’s book for some Mosaic designs that are not as geometric as typical Overlay and Inset Mosaic. Basically, go play with color.