121made of paper (shoji). The filter layer itself can assume vari-
ous dimensions, and may form a > layering with its own spa-
tial extension (> space-containing wall).
On the one hand, filters demarcate separations, on the
other, they modify our perceptions; depending upon the con-
stitution of the filter, individual modes of perception are fil-
tered out, i.e. seeing through glass without hearing, listening
through thin, opaque wall screens without seeing. As modula-
tors, window shutters in various positions regulate the perme-
ability of window openings. Graduated differentiations admit
light, for example, while closing off the > gaze towards the
outside or allowing only schematic views, securing privacy
while providing hints via the play of shadows. The curtain ef-
fect, achievable through lamellae, latticework and mesh struc-
tures, allows views only from dark into lighter areas. This not
only veils views from the outside, but also weakens the inci-
dent light or causes it to vibrate. Venetian blinds, for example,
allow views towards the outside to be finely controlled while
allowing occupants to remain invisible from the outside. Fresh
air is allowed to enter, while the public space outside remains
obscured. Within, the unifying effect of the light, fragmented
into stripes, blurs spatial boundaries and produces shimmer-
ing atmospheric effects.
By fragmenting sensory impressions, differentiated filter
systems activate and develop the contributions of the individ-
ual sensory modes in a targeted way. In the Japanese house,
for example, in contrast to the explicit definition of the func-
tion of > openings in western culture (i.e. > door = exit, > win-
dow = views, > wall = separation), the functions of doorways
and windows are blurred. They are not kept distinct from the
dividing function of the wall; instead, screens, sliding doors
and shutters become gradually adjustable filters. Seen from
the inside, filters generally have the ambivalent effect of grat-
ings and fences: as barriers to the outside, despite their perme-
ability, they create feelings of security, but may also attribute
to sensations of confinement. From the outside, the effect is