This sketch was made on August 27, 2010 with my 4-inch TV102 refractor. subsequently I observed this planetary nebula on September 29, 2011 with my 10-inch dob. Since I did not sketch it again, I will share some notes derived from this latter observation with the sketch using the 4-inch refractor.
Using the 10-inch Newtonian reflector, I star hoped to the nebula using a 15mm panoptic eyepiece that gave a magnification of 80x. At this magnification the nebula looked like a small blotted star. I then upped the magnification to 120x with a 10mm radian eyepiece and at this magnification the central star was very pronounced with direct vision. When using direct vision the nebula was faint and looks like a mist around the central star. When looking about half way to the edge of the field-of-view and looking at the nebula with averted vision, suddenly the nebula much brighter than the central star, almost like a bright ball of light. Repeating this direct vision, averted vision and back to direct vision several times, made the nebula appear to blink on and off.
This sketch using the 4-inch refractor looks very similar to the direct vision view using the 10-inch reflector.
The challenge with this object is seeing the faint outer shell of the nebula. Seeing this shell takes really dark transparent skies and mine were much to light polluted to see this feature. Here is a photograph that shows the faint outer shell of the Blinking Planetary Nebula. The next time your at a truly dark site look for this feature. You just might see it.