Cardstock is the material for fine cutting: invitations, templates, models, fretwork impossible by hand. It needs almost no power, but forgives very little.
Settings: what really matters
Work at minimum power and maximum speed. The right setting is the one that barely cuts: as soon as you leave margin, the line yellows half a millimetre either side, and that shows on an invitation.
For a clean fold (scoring), a single very low-power pass marks the fibre without going through: folding becomes straight and consistent.
Paper moves at the slightest draught. A honeycomb bed and, if needed, a few magnets on the edges stop a sheet lifting mid-cut — the number one cause of failed cuts and fires.
Risks and finishing
Paper ignites instantly and fire spreads across the whole sheet in seconds. This is the material where "never unattended" is most literal.
Avoid metallic, plasticised or laminated papers: the film is often an unknown plastic, sometimes chlorinated.
Smoke marks come off with a kneaded eraser. On light paper, masking tape on the visible face during cutting remains the best prevention.
Every figure on LaserSettings comes with the machine, the laser source, the material and the thickness it was tested on. A setting published for a 10 W diode says nothing about a 40 W CO2, and a setting for 3 mm says nothing about 6 mm: check those four things before you copy any number.
Settings are confirmed or disputed by the members who reproduce them, so reliability comes from cross-checking rather than popularity. Photos of the result — cut edges, engraving shades, scorching — tell you more than a single number found on a forum.
Whatever the material, treat a published setting as a starting point: run a small power/speed test grid on an offcut, clean the lens, redo the focus, work with fume extraction and air assist, wear glasses rated for your wavelength and never leave the machine unattended.