You want a small film representing some of the features you want,
repeated a few times.

  A suitable film can be generated with a computer, with a postage stamp
sized design containing most features you are interested in reproducing,
repeated on a strip. 5 copies are enough, with each copy about 20x20 mm^2.

  Place a strip of sensitized board in the machine, put the film on it,
and use an opaque plate to cover all but one of the designs. Expose 1
minute, then move the opaque plate to have 2 designs exposed. Expose
another minute. The next exposure is 1 minute etc. The last exposure of 1
minute is without any cover.

  When you finish this, your strip will have the 1st design exposed 5
minutes, the 2nd 4 etc. Develop the board and inspect the designs with a
magnifying glass. Pick the best one. It helps if you draw squares on the
board before you start, and number them 1..5 with a felt tip pen
(indelible waterproof black). Each square should contain a copy of the
test pattern. Of course you can do it in the computer (but some brain-dead
board drawing programs won't let you). The lines and numbers will survive
the exposure and developing.

  You may have to move the lamps farther away. This will increase pattern
sharpness. Exposure times under 1 minute are critical on operator
precision with such equipment (do you use a timer ?).

  Develop the board according to the photo-resist's
manufacturer's indications, and keep an eye on the temperature and
concentration of the developer.

hope this helps,

Peter