Microtek ScanMaker 35T Plus User Manual page 22

Click on the
2
To see how the cursor lines work, draw a scan frame. Click on
the top left corner of the image as your starting point, then drag
down to form a scan frame.
As you draw the scan frame, cursor lines will appear to help you
draw the scan frame precisely. When you release the mouse,
your scan frame will be aligned with the cursor lines.
Click on the
Scan Frame
tool, then
define a
starting point.
Scan Frame tool.
As you drag the
mouse down, the
scan frame is
aligned with cursor
lines on the x and y
axis (based on your
selected option in
the submenu).
Reference 17