So a tetra blanket, or simply "tetra", here, is the gauze-like, loose cotton knit cloth used very often in baby care. Like the good monkey that I am I copied the way I saw it folded while in the baby hotel that we stayed in after the birth. The tetra was folded into a square and placed under the babies head in the stroller. It took me a nice couple of months but I fell in love with a new method. Maybe others do this all the time, but I felt as though I had invented the wheel. Aha!