To work poster pens are very convenient, and who was fine — what makes them miracles: you can always pick up the desired width of the line, replacing the pen on the right more. But each can hold only one “track”. But this small improvement allows us to obtain two parallel lines… in a single pass. For this, needle files propisyvaetsya portion of the working edge of the Pera: are formed like two pens in one.
Recommend to read
SMALL INCUBATOR
An incubator for breeding chickens at home can quickly to make, having a thermostat with indicator light on and the cord with plug (eg, burnt-out iron), a couple of 300 Ohm tubular...
LENS FOR… MOBILE PHONE OR POCKET KVN
In the early XIX century the French scientist Augustin Jean Fresnel has created an unusual lens, which are not brushed solid piece of glass with a spherical surface, and a set of...