Thanks Dogsbody. Indeed, sutra copying is very mind soothing, though really difficult. Characters are extremely small (1-2 cm) and also they need to be perfectly aligned.
Here is one more in silver ink. I gave a size reference to a Polish coin (17,5mm in diameter). This calligraphy is written with a small brush made of weasel hair (highly responsive tip), with hanging arm technique (entire arm lifted) and kana script brush grip (by the end of the brush axis) for maximum freedom of movement. It is also written in one continuous brush stroke. The signature characters are smaller than 1cm.
飛龍 flying dragon