The Importance of Cap Cut for Accurate EEG Recordings

While Electroencephalography (EEG) plays a crucial role in a variety of fields, from neuroscience research to clinical diagnosis of neurological conditions, achieving optimal recordings relies on several factors, including one often-overlooked detail: the EEG cap cut.

Easycap GmbH understands that there is no universal cap-cut; one size does not fit all. As such we are proud to be the only EEG cap manufacturer offering two distinct cap cuts:
the A-Cut and the C-Cut.

This allows us to ensure optimal fit for individuals with varying head shapes, ultimately leading to superior data quality and enhanced participant comfort.

How to Recognise Cap Cuts

Participant comfort is crucial for gathering accurate data. That's why we offer two distinct cap styles, A-Cut and C-Cut, designed to accommodate the diverse head shapes found globally.

Figure 1: In this bird's-eye view schematic, the profile of the A-Cut is subtly more round than the C-Cut, which is more oval
  • C-Cut: designed for oval head shapes. It is the first choice of laboratories located in America, Europe and India.
  • A-Cut: designed for round head shapes. It is favoured by laboratories located in China, Japan and Korea or by any other lab with participants with North- and East Asian heritage.
Figure 2: Cap cut is indicated on our caps with a blue (A-Cut) or green (C-Cut) label.

Starting from May 2024, all of our caps will come with a hand-sewn label indicating their cut, making it possible for researchers to identify their equipment at a glance.

Example order codes for 64-Channel standard actiCAP snap caps with C-Cut and A-Cut variants are:

  • CACS-64-SCMW-56
  • CACS-64-SAHW-48

This option comes at no extra cost! Simply specify which cut you need when ordering from us or our distributors, or here on our webshop if you are in the EU.

The Science Behind Cap Cuts

Head shapes come in a diverse spectrum, with one prominent distinction lying in the degree of roundness. Individuals of Asian descent, for example, tend to have more rounded head shapes, while individuals of European descent often have more oval-shaped heads (Ball et al, 2010). These subtle yet crucial differences can significantly impact the fit and comfort of a "one-size-fits-all" cap.

A poorly fitted cap can lead to several issues:

  • Electrode displacement: Improper positioning of electrodes due to poor fit can compromise the accuracy of recorded brain activity.
  • Increased impedance: Loose contact between the electrode and scalp, particularly in occipital regions, can lead to higher electrical resistance, hindering signal quality.
  • Discomfort and movement: A poorly fitting cap can be uncomfortable to wear, leading to participant movement and introducing artifacts into the recording.

These issues highlight the importance of using well-fitting caps. By offering both the A-Cut (designed for rounded head shapes) and the C-Cut (designed for oval head shapes), we provide researchers with the precision tools they need to acquire reliable and accurate EEG data.


Ball, R., Shu, C., Xi, P., Rioux, M., Luximon, Y., & Molenbroek, J. (2010). A comparison between Chinese and Caucasian head shapes. Applied ergonomics, 41(6), 832-839.

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