This technique is also referred to as Invisible Machine Applique'.
I'm teaching a workshop on this form of applique' at Quilter's Corner in August. This block is one of several "sample" pieces I've made for show & tell. What I love about this method of machine applique' is that it doesn't involve raw edges or fusible web. It has the look and feel of needle turn applique'. I love to do hand applique' work - but there are only so many hours in a day.
During August and September, I will begin sharing with you a series of BOM applique' projects that I've commmitted to thru the end of 2013. 2 of these projects will be hand applique' work and 2 will be sewn via heirloom Machine Applique'. It will be fun to see if you can tell which method I used in each quilt.
On to another topic: Here are the Easy Peasy T Blocks I've made for Month #3 of our Vintage Rouge Sew-along. There are 20 T Blocks to make this month for the quilt.