Frequently Asked Questions

Understanding Twain Drivers

Twain is a computer industry standard which specifies how image acquisition devices such as Scanners, Digital Cameras and other devices transfer data to software applications. Twain allows software applications to work with image acquisition devices without knowing anything about the device itself. If a device is Twain Compliant and a software application is Twain Compliant, the two should work together regardless of whether or not the software was bundled with the image acquisition device when it was purchased.

Before the advent of Windows and Twain, users and developers faced the difficult dilemma of drivers. For every hardware device owned, you would need a driver for every software program you owned. When there were only three different printers and three different programs, only nine drivers were needed. But as the number of printers, programs and other devices grew, so did the number of drivers needed.

There are currently over 200 different printer types, over 20 image editing packages, and over 20 different scanners. If every image editing program was to work with every scanner and every printer there would be 80,000 different drivers to make everything work with everything. Obviously the market couldn't survive like this, either some items would go unsupported or the industry had to find a better way. Enter Windows.

Windows changed the way people looked at peripherals. All printers are essentially the same, varying only in details and implementation. What Windows did was to develop generic print services. So any program that wanted to print would just print to the generic device and let Windows handle the specifics.

Twain is the standard that does the same for scanners. All scanners basically produce the same type of information, varying only in detail and implementation. The Twain specification was written by a group of eight hardware and software companies. The acronym means Toolkit Without An Interesting Name. Twain driver, Twain interface and Twain module are all synonyms for a software module that allows image editing, optical character recognition, desktop publishing and fax software to deal with the scanner in a generic way. Users don't need to determine if ,"XYZ" program supports scanner "ABC" before they buy it, instead they just look to see if both support Twain.

Through Twain and Windows, the number of required drivers drops from 80,000 to a mere 220... now that's progress!

All Mustek scanners support Twain. Some popular Windows programs that support Twain are: Adobe Photoshop, Corel Photo Paint, WinFax Pro, PageMaker, Picture Publisher, iPhoto Plus, Fractal Design Painter, Microsoft Publisher, Wordlinx OCR and Text Bridge OCR.

The diagram below shows how Twain modules work:

It is possible to attach more than one Twain Compliant image acquisition device to a computer at the same time as shown in the above diagram. Each of the devices will have it's own separate Twain module. This makes it necessary for Twain Compliant software applications to provide a means for the end user to select which Twain device to use during a session. Most Twain compliant applications have a function on the File Menu which allows selection of the Twain Source or Acquire Device. The Twain Source that is currently selected will be the one called up when the acquire command is activated.