Best Pencils for OMR Bubble Sheets: 2025 Exam Prep Guide

Q: Which pencil setup keeps OMR scanners happy for 2025 exams?
A: Stick with opaque 2B wood-case pencils (plus backups), pair them with spiral-shading drills, and pack erasers that lift carbon cleanly so scanners read every bubble first time.

TL;DR
Use an opaque 2B wood-case pencil for any paper OMR paper unless the exam explicitly says otherwise; shade each oval with three light spirals instead of one heavy drag.
Keep a spare pencil + vinyl eraser in a clear pouch, and rehearse filling five rows in 20 seconds so you do not choke on pacing.

1 | Why bubble sheets care about graphite density

Older OMR scanners shone blue light through the sheet, so they only picked up very opaque marks-hence the long-running “No. 2 pencil only” warning. Modern machines read reflected light instead, but they still prefer mid-soft graphite because hard $H$ leads stay too faint and soft $B$ leads smudge easily. (Bloomfield, 2006) In Singapore, interpret every “No. 2” note as 2B-SEAB still issues PSLE and GCE answer sheets that expect 2B shading, so carry exam-grade 2B sticks by default and only swap to HB if the invigilator explicitly says so.

Good mental model: you are laying down a thin film of graphite. The denser the layer, the darker it looks to the sensor and the easier it is to cleanly erase if you change your mind.

Because each exam body tunes sensitivity differently, default to whatever they specify on the admission ticket. When in doubt, the safe bet is a freshly sharpened 2B pencil with an intact eraser.

2 | Wooden pencils that survive timed shading