Technicians form handsheets in a sheet mold from dilute stock, then press and dry them by a fixed procedure before testing optics and strength. Because the forming steps never change, differences between handsheets reflect the pulp and additives rather than the paper machine. Optical handsheets are often made without filler or retention aids so the pulp's own brightness and scattering show clearly.
Make a set of handsheets from the new pulp and run scattering coefficient before they commit to the switch.
Also heard as
- lab sheet
- test sheet
Related terms
Brightness pad
Thick, flat test disc formed from pulp slurry so brightness can be read on an opaque surface.
Conditioning
Bringing paper samples to a standard temperature and humidity before testing so results can be compared.
Furnish
The recipe of pulps, fillers, dyes and chemicals that make up a paper grade's stock.