is it possible to use an apple pencil without using a screen protector for the ipad

Last question first...

Yes, you can use a cleaning wipe, moistened with 70% isopropyl alcohol, to gently clean your iPad screen. Be aware that regular or aggressive cleaning will eventually remove the sacrificial oleophobic coating from the screen.

Screen Protectors

As for using a screen protector, this is largely personal choice - but there are considerations. Armed with an understanding of “how” a screen can be damaged will help you to make an informed decision.

While an Apple Pencil has a soft tip that is intended to protect the screen from damage, basic material science tells us that a hard abrasive material (such as microscopic grit - present in many environments), will embed in the softer of two materials. Once embedded, the very hard material can be repeatedly dragged across the screen - and cause damage.

A fingertip can easily “feel” grit an other abrasive contaminants - which you will instinctively not drag across the screen. When using a pencil, you cannot directly feel potentially damaging surface contamination.

iPad screens are robust, but the anti-reflection treatment and oleophobic coating can be easily damaged by tiny grit/dust particles that are unavoidable in many environments. The oleophobic coating is a chemical sacrificial layer that will wear-out over time.

Your iPad screen is the single most expensive component of your iPad - whereas a screen protector is sacrificial layer that, if damaged, is easy and relatively cheap to replace.

Also consider that physical screen protectors can be removed without affecting your iPad warranty. Liquid screen protector products offer no physical damage protection, are irreversible, and may void your Apple warranty.

Some Users happily use their iPad without a Screen Protector - and report no issues whatsoever. Others prefer the additional protection offered by a good quality Screen Protector. A further subset of Users have suffered damage to their unprotected screens - and when confronted with the cost of a screen repair, retrospectively wish that they had opted to use a Screen Protector.