An independent guide device is positionable on the supporting surface of the plate and in intermittent contact with the feeder of a sewing machine for guiding the needle of the machine in an irregular pattern. The guide device comprises a pair of complementary jig devices shaped to fit in juxtaposition with layers of material to be sewn to each other positioned between the jig devices. The jig devices have the same irregular configuration and complementary cross-sectional areas. Clamping devices releasably clamp the jig devices in juxtaposition with the material to be sewn positioned therebetween. Guide members extend from the foot device of the sewing machine for maintaining the guide device in a predetermined position relative to the needle of the machine while the guide device is moved between the foot device and the supporting surface of the feeder of the machine through the entire duration of the guide device.