What are Pickguards?
A pickguard is a cover applied to a guitar's surface and is usually made from plastic, although metal and other materials are sometimes used. They come in many shapes for different guitar models and are an integral part of the overall aesthetic.
Pickguard or Not?
Pickguards are believed to protect the guitar's finish from scratches, such as pick scratches while playing and fingernail scratches caused by slapping. They also cover up wire routs cavity, and avoid the irritatingly long drill bit. Sometimes they don't cover up anything at all and are purely decorative, beacause it's something easily changed that can make a guitar look completly different.
But the decision is yours whether to have a pickguard or not. Some guitar builders don't like the pickguard, because they think it's ugly, or it's a lazy way to cover all up with that.
Do Pickguards Impact Guitar Tone?
Pickguard is anyways an intergral part of a guitar and involved in the field, having different types of material, weight, shape, it must have something to do with the tone. However, the truth is, only the most finely tuned ears will notice a dramatic difference in tone. That's why we don't necessarily have to consider this effect when choosing a pickguard.