Nimitta Time

The nimitta (as described on page Forty-Seven) of breathing meditation varies according to the individual, it could be like fine wool, cotton air, venus, a plant, a piece of wood, a cobweb, mist, a lotus, a chariot wheel.  Sayadaw points out that it is usually like cotton wool, and differences are due to perception.  I found a nice essay by a Theravadin Canadian monk at Arrow River on the ins and outs of nimitta.