Observing ornamental paper in Southen Sung Dynasty on "Pine Wind Pavillion Poem" , I think Northen Sung calligraphy was produced among more dainty circles than I had thought.
Beutiful ornamental papers are often used for 
calligraphy in later Heian period Japan(11-12th century).
We sometimes appreciate the ornament than  the calligraphy.
This is detail  of Hon-AMI-GIRE( a copy of "KOKIN-SYU", 11th century).
This flower printed paper is regarded imported paper from  Sung dynasty china.
Waxed papers and Quolong Emperor Style papers
in  Ching dynasty are colourful, but most chinese calligraphies
are written on white paper.
In Sho-so-In Collection( Nara, Japan)  has colorful dyied papers
on which imaginary animals  among clouds are drown.
Maybe, it reflects later Tang taste.
Later Heian period  ornamental paper was imported from Sung dynasty china,
at least 11th century.
Since a lot of such ornamental papers have survived for 800 years,
  the amount imported
was very large. It shoud be  internatinal manufacture business at that time.
I felt strange that we couldn't many ornamental papers 
among chinese calligraphies survived  from Song dynasty.
Many scholars regarded such ornamental papers have survived only in Japan, and
not in China.
However, I've concluded that several ornamental papers survived with chinese
calligraphy from 11th century.

This handscroll "Pine Wind Pavillion" is the representative of
Huang Tingjian(1045-1107)
on its quality, history, style, and condition.
In November 1999/11, I found large floral patterns printed on the paper.
On each sheet of white paper, one glove of  Vegetables and flowers is 
daintily printed with white. They are refined and gorgeous.  Usually, you overlook it.
Changing your viewpoint to  a sharp angle, you can see these patterns on the paper. 
Before then, I appreciated this handscroll two times, but I couldn't
find them.
All Photographes (I saw) can't take these patterns. However, these pictures 
show white/light lines and bands in strokes of brashes. 
When writing with brush on pattern printed paper, it often happened.
These light lines are traces of patterns.
Recently  I aquired  its coulour colotype  reproduction. Amazingly, the patterns  are clear on it. It is  clearer than  the real which  I  found in National Palace Museum in Taipei. Some photograph  technique may have it  more distinct.
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These pattern changed my impression on this masterpiece. I thought it a simple, strong, and stoic. Now I think it refined and gorgious masterpice to gift for VIP.
Are there another calligraphies on such ornamented paper?
An-chi(1683- ?) described  such ornamented papers about some calligraphies  in his  catalogue(ACE 1743).
Folowing An-chi, in 2000, autumn, I found "Tao-shen Tie" bi Cai-xiang(ACE1012-1067) on  an decorated paper 
in National Palace Museum in Taipei.  The  pattern  is  more  modest than "Pine  Trees" and likes brocade pattern.  
In OSAKA MUNICIPAL MUSEUM, OSAKA, has "Li-Pai Poems" by Su-shi(ACE1036-1101) which  is  former ABE-collection. Its paper  has  gooses and leeds picture  style decoration. These white  lines became  very faint so difficult to observe. I had doubted  its  authenticity  for  such decorated paper. Descovering  "Pine Tree" ornament, I have thrown away  such  suspicion. 
Searching  carefully, such  examples  will  become increase.