ACADEMY: E-SIGNING Signature Capturing Technology

Signature Capturing Technology

Some technical background on suitable technologies for signature capturing like electro-magnetic resonance

SOFTPRO provides an extensive overview about supported
Capturing Devices

SOFTPRO recommends using capturing devices that operate on Electro-Magnetic Resonance (EMR). There is no better technology to capture "clean" signatures, evidential and high in quality.

Signing with EMR is very ergonomic: Signers can comfortably rest their hands on a tablet's surface without affecting the signature quality.

Pioneering Electro Magnetic Resonance: Wacom

SOFTPRO hardware partner Wacom holds stunning 80% of the Global Pen Tablet Market*. They provide their components  for Electro-Magnetic Resonance under the Label "Feel IT" (prior to 2009 also under the term: "Penabled") to many Third Party manufactures. Their components are integrated into devices with and without LCD screens. * Source: Wacom Annual Report 2013, p.16

Back in 2007 Wacom joined forces with SOFTPRO to develop its first tablet primarily designed to capture signatures. The result was the SignPad eSignio (Wacom STU-500). Today SignPads are the preferred choice for all professional users taking signatures seriously.

More than 400,000 Wacom Signature tablets of the STU-series have been installed worldwide by early 2014. They are used in banking, retail, government, telecommunication, postal services, service industry,…

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How Electro-Magnetic Resonance works

Sandwich Structure of a Signature Pad or other Signature Capturing Devices based on Wacom Electromagnetic Resonance Technology - © Image: Wacom zoom Sandwich Structure of a Signature Pad or other Signature Capturing Devices based on Wacom Electromagnetic Resonance Technology - © Image: Wacom

Beneath the surface of the pad there are horizontally and vertically oriented antennas, moving within microseconds between transmission and reception mode. Electro-magnetic waves enable to determine the position of the pen using triangulation. An electro-magnetic signal stimulates a resonant circuit comprising coil and capacitor in the pen to oscillate.

The resonant circuit behind the pen tip is supplied with the pressure on the pen tip and serves as a transmitter. The received signal passes through the modulator to the chip. The information from the pressure sensor (capacity) of the side switch go to the chip. From there they enter the modulator, which returns a signal to the resonant circuit in the tip. From there it is sent back to the tablet – for example in a SignPad.
  • no battery required: no hassle with leaking or empty batteries
  • no cord required to carry an electronic signal
  • Since no electronic signals are passed through the pen tether, pen operation cannot be affected by damage to the tether

A digitizer overlain on the LCD screen creates an electromagnetic field. When the pen comes in contact with the screen's electromagnetic field, its motion is reflected on the screen as a series of data points. As the pen continues to move across the screen, the digitizer collects information from the pen movement in a process called "sampling."

The digitizer samples "pen events" - units of motion that correspond to data points - per second. These electromagnetic pen events are then represented visually on the screen as pen strokes. The sample rate of events per second of devices with Wacom Penabled Technology inside is for example

Signals per second Device Type

SignPads (Wacom STU-Series)Wacom DTU-1031 Interactive Pen Display
Android Tablet: Olivetti Olipad Graphos
Windows Tablet PCs with "Feel IT" or "Penabled" Technology - e.g. Toshiba WT310 / Portégé Z10t


Android Smartphones: Samsung GALAXY Note, GALAXY Note II & GALAXY Note 3
Android Tablets: Samsung GALAXY Note 8.0, GALAXY Note 10.1 & GALAXY NotePRO 12.2
Windows Tablet PCs with "Feel IT" or "Penabled" Technology - e.g.
Asus VivoTab Note 8
Fujitsu Stylistic Q584 & Stylistic Q 704
Lenovo ThinkPad Tablet 2, ThinkPad Helix & ThinkPad YogaMicrosoft Surface ProSamsung ATIV Tab 3 & ATIV Smart PC

Windows Kiosk System
DESKO Tablet Kiosk

Resistive Touch

Alternative methods to electromagnetic resonance are based on touch response. Different terms are used for this technology. For example "touch-sensitive resistance" or "force sensing resistors". The abbreviation "touch pad” is very common.  

With this technology, the sensor consists of a sandwich of two conductive coated plastic film. This sandwich is as a top layer on the signature pad. The action of pressure changes the electrical resistance of the sandwich. The detection of the location and intensity of pressure is thus on changes in distance between the two plastic sheets by the pin.  


Signature pads and tablets based on this technology tend to degradate faster and show ugly scratches.

The technology is less reliable in demanding environments where high volumes of signatures need to be captured every day. As a consequence some manufacturers exclude touch sensors completly from any warranty. Others exclude the "normal wear and tear"  so it remains unclear if a display with scratches sors may be exchanged free of charge or not. 

Most manufacturers of these type of devices offer a standard warranty of two years only. SignPads and the Interactive Pen Display DTU-1031 come with a three years warrranty.


This SignPad eSignio (Wacom STU-500) was installed in 2009 at a clerks desk at Caja España. The image was captured in May 2013 when this particular SignPad was in operation for four years. Every working day between 500 and 1000 signatures are captured for transactions and contracts per SignPad at a workstation of a clerk at Caja España.

Other pads are used by agents for contracts and some other major transactions. They capture between 50 and 100 signatures per SignPad every working day. Lowest usage of SignPads is at branch Manager desks: They use to capture around 50 signatures for contracts on a SignPad.

Santiago Uriel, Technology Vice-Secretary of the Spanish Savings Banks Organization CECA, April 2013:

"Since the first signature has been captured in 2009, more than 300 million documents have been signed via the signature pads and they all look nearly new. In all those years we only had to complain less than 30 – that is a failure rate of less than 0,1%.”

Comparison Electro Magnetic Resonance & Resistive Touch

There are four major benefits when choosing devices with electro magnetic resonance instead of those based on resistive touch technology.
  • Durability It is not possible to equip the surface of the pad with a fully durable and scratch-resistant glass surface. Some pads only have a simple plastic foil covering the surface, When signing, this plastic foil bends which can be seen when looking onto the tablet form a shallow angle. The plastic foil can easily be scratched or damaged and signatures do not look natural and like given on paper.
  • Accuracy: Drawing straight lines may not automatically result in straight lines captured as data. The precision of locating the pen is not high enough and results into data being capture inexact. In extremis the signatures captured on these devices are so different from the signatures of persons given on paper that they should not be accepted as legally binding signatures of a person at all.
  • Pressure Levels: Very reliable capturing, calibrated and evenly spread without interpolation. The quality of captured signature data is easily recognized when signatures run through an automatic verification process for example using SOFTPRO SDK SignWare.
  • Color Transmission: A display with of a pad with a EMR sensor below looks brighter and crisper for a longer time.

Dual Input Mode Devices: Active Pen and Touch

Some Tablets use a combination of active digitizer and touch technology. HP and Lenovo offer the option to order Tablet PCs that leverage Wacom's Reversing Ramped Field Capacitive (RRFC™) touch technology too. They have two sensors: one for pen with electro-magnetic resonance another for inger touch. When using such a device make sure the pen sensor is activated (similar to devices where you can choose between track ball and touchpad as substitue for a mouse).


The special activize digitizer "Samsung S-Pen" is light and thin (diameter 6.5 mm). S-Pen devices launched in 2012 and later can distinguish 1,024 levels of writing pressure. The pen and digitizer technology of the S Pen is provided by Wacom. 

Samsung and Wacom signed a capital and business alliance agreement on January, 30 2013. The goal of the alliance is to establish a broad strategic partnership in the smart phone and tablet areas.

SignDoc Mobile on Samsung Galaxy Note 8.0 with S Pen

Active Digitizer Technology in Tablets and Smartphones


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SOFTPRO recommends to prefer devices running on electro-magnetic resonance for best results when capturing handwritten signatures. Electro-Magnetic Resonance (EMR) Technology

The so-called "Penabled" technology of SOFTPRO Partner Wacom is integrated in

  • Tablets running on Android: Panasonic Toughpad FZ-A1Olivetti: Olipad GraphosSamsung: GALAXY Note 8.0, GALAXY Note 10.1, GALAXY NotePro 12.2 Toshiba Excite Write, Wacom Cintiq Companion Hybrid* 
  • Tablets (Slates and Hybrids) running on Windows 8 Professional - e.g. Asus VivoTab Note 8 and VivoTab; Dell Latitude 10; Fujitsu Stylistic Q704 and Stylistic Q584; HP: Pro x2 612 G1; Lenovo: ThinkPad 10, ThinkPad Tablet 2, ThinkPad Helix and Think Pad Yoga; Microsoft Surface Pro 2, Motion Computing J3600; Olivetti: Olipad Graphos W810, Panasonic Toughpad FZ-G1; Samsung: ATIV Tab 3, ATIV Smart PC; Toshiba Portégé Z10t; Wacom Cintiq Companion
  • Smartphones running on Android like Samsung GALAXY Note 3 or Asus Padfone Note 6
  • Last but, not least on on most Pre-Windows 8 Tablet PCs running on Windows 7 like Slates – e.g. Asus Eee Slate B121, Panasonic Toughbook CF-H2 Field, Samsung PC 700T - Serie 7 Slate Convertibles – e.g. Fujitsu: Lifebook T904, Lifebook T902, HP: EliteBook 2760p, Lenovo: X230t

* The Wacom Cintiq Companion Hybrid also runs as Interactive Pen Display when connected to a Windows PC

Wacom EMR Technology in Kiosk Systems for POS


The DESKO Tablet Kiosk is another fine example for a signature capturing device with built-in Electro-Magnetic Resonance Technology provided by Wacom. DESKO Tablet Kiosk

Dual Input (Pen & Touch) of N-trig

N-trig's DuoSense® solution is a dual-mode interface, powered by a single device, utilizing both pen and projected capacitive multi-touch functionality. This solution utilizes N-trig’s Digital PencilTM, which enables direct on-screen digital input. The solution was introduced to the Tablet PC market in late 2007. The DuoSense uses a single digitizer rather than having a panel with two layers.

SOFTPRO E-Signing solutions also run machines with built in N-trig DuoSense technology such as
devices running on Windows OS Slates – e.g. Acer Aspire R7-572, Fujitsu Stylistic Q 552, Microsoft Surface Pro 3, Motion Computing CL 910,  Sony Vaio Tap 11, Sony Vaio Duo 11, Sony Vaio Duo 13,  Convertibles – e.g. Dell Latitude XT3, Fujitsu Lifebook T 580
Test SignDoc with one of the devices mentioned above for free now Download SignDoc Desktop Setup

For devices with n-trig digitizer running on Android OS Smart Tablets – e.g. Casio Tablet, HTC Flyer, Lenovo ThinkPad K1 Tablet, Motorola Droid XYBoard 10.1"
check SignDoc Mobile App for Android 

SignPads capture data using Electro Magnetic Resonance (EMR). This technology is also build in an increasing number of tablets running on Android or Windows-Betriebssystem.

The benefits of EMR compared to alternative technologies as implemented in SignPads and other tablets are outlined in a whitepaper available to SOFTPRO customers, partners and prospects. Inquire for access to this whitepaper via your contact displayed in the right column of this page.

While every care has been taken in the compilation of the information listed above, SOFTPRO gives no guarantee as to its currency, accuracy or completeness.