FR4 fibreglass board can be cut, but it requires the right technique because the fibreglass dust and fibres produced during cutting are an irritant.

Safety first: Work in a well-ventilated area. Wear eye protection and a dust mask rated for fine particles. Do not use power tools that generate large amounts of dust (table saws, rotary tools at high speed) unless you have adequate dust extraction.

The best methods for clean cuts:

• Score and snap: Use a sharp utility knife and a straight edge. Score the cut line firmly several times on both sides of the board, then snap along a hard edge. This works well for straight cuts and produces minimal dust.
• PCB shears or guillotine cutter: Gives clean, straight cuts with no dust and no blade wear. Ideal for repeated cuts.
• Hacksaw or fine-tooth hand saw: Clamp the board securely. Cut slowly.

After cutting, smooth and clean up any edge fibres with a fine file or light sandpaper. Check that no stray copper or fibreglass is bridging any traces near the cut edge.