Scanning presents one of the biggest challenges for archivists. The best way to get comfortable with scanning is to understand what all the different options mean and how to choose the right ones. All of that is covered in the Scanning 101 workshop.

Choosing the right PPI when scanning images.

The diagram below will help you quickly determine what PPI to use to scan an image. For type-written and typeset documents, you can generally use 300 ppi, but for images, the choice depends on the quality of the original and what you intend to do with the scan.

Scanning decision tree

Read the full explanation of the diagram above and see examples of the differences between scans made at different resolutions.

How PPI and color affect file size

  • An image that is scanned at 600 ppi will produce a file that is 4 times the size as one scanned at 300 ppi. That's right, four times larger, not two times. Think about it this way. If your kitchen floor has tiles that are 12" squares, each tile occupies 1 square foot. But if they were 24" squares, they would each occupy 4 square feet.
  • A resolution of 300 ppi is plenty for letter-size documents that are primarily text. And unless the documents contain color, they can be scanned using 8-bit Grayscale. An exception would be, for example, a type-written page that had been written or doodled on using a colored pen, or if the page contained a color image. A resolution of 300 ppi is also fine for OCR (optical character recognition) purposes.
  • An image scanned as 24-bit color, will produce a file that is 3 times the size as the same image scanned as 8-bit Grayscale. That's because 24 bits is 3 times as many bits as 8 bits.

When using Grayscale, choose 8-bit, not 16-bit. A 16-bit scan will produce a file that is twice the size as when using 8-bit with no perceivable difference in quality. The only time to use 16-bit is if you plan to perform heavy post-processing of the image using a program like Photoshop.

Typical scanner settings

The most common settings for scanning a color image using the Epson scanner software are shown in the screenshot below. The biggest variable is the Resolution setting which can range from 300 ppi to 1200 ppi depending on what you are scanning. You'll also change the Image Type from color to grayscale when scanning black & white documents or images. Don't change the Document Size because it's set automatically to the scanner table size or to the size of the marquee you drew on the Preview screen to delimit the scan area.


Choosing the output file location type

To set the location and type of the output file produced by the scanner:

  • Click the File Save Settings button next to the Scan button (looks like a folder and a photo).
  • On the File Save Settings dialog shown below:
    • Choose Other for the Location.
    • Browse to the folder where you want to save the scans.
    • Set Image Format to TIFF or to PDF (never choose any of the other options).
      Learn about creating PDFs from scans to choose the right image format option.
    • Click the OK button.


Performing the actual scan using the Epson Scan software

Follow these steps to scan an image or document that you have placed on the scanner table.

  • Click the Preview button.
  • The scanner will quickly scan the entire scanner table and display the Preview screen.
  • On the Preview screen:
    • If the preview is not rotated correctly, correct it using the rotate left or right buttons.
    • Move the mouse over the preview area. The cursor will change to a large plus (+).
    • Click the mouse at the upper-left corner of the item to be scanned and drag to the lower-right corner.
    • When you release the mouse, a dashed rectangle (the marquee) will delimit the area to be scanned.
    • Adjust the scan area if necessary by moving the cursor over the rectangle until the cursor changes to a double-headed arrow, then click-drag to adjust.
  • On the main EPSON Scan dialog, click the Scan button.
  • The scanner will operate, and when finished, it will create a file.

When scanning several items that are the same size, you only need to perform the preview step for the first item. After that, you can put the next item in the same place on the scanner table and just click the Scan button.

Scanning multiple items at the same time

You can save a lot of time when scanning small items, such as snapshot-sized photos, by placing multiple items on the scanner table and scanning each of them in a single operation. When you follow the steps below, the scanner will scan each item one at a time, which takes time for each scan, but you will spend less time opening the scanner lid, placing items, closing the lid etc.

  • Click the Preview button.
  • On the Preview screen:
    • Perform the same operation described above to draw a marquee around the first item.
    • Release the mouse button, move to the upper-left corner of the next item, and click-drag a marquee around it. The dashed rectangle on the first marquee turns to a solid rectangle.
    • Repeat for each item.
    • When done drawing all the marquees, click the All button. Dashed rectangles will appear for all of the marquees as shown in the screenshot below. If you don't click the button, only the selected marquee gets scanned.
  • On the main EPSON Scan dialog, click the Scan button.
  • The scanner will scan the area delimited by each marquee, one at a time, and create a separate file for each marquee.


There are buttons in the Marquee section of the Preview screen that you can use when drawing marquees, but just following the steps above will be quickest and easiest most of the time.

Preview tips

  • Drag the Preview screen window to make the preview area larger.
  • Use the Zoom button to zoom in on just the area delimited by one marquee. Do this when you need to make a more precise selection.
  • Use the Delete key to delete the currently selected marquee(s).
  • Move a marquee by click-dragging inside (the mouse turns to a hand).
  • If you are selecting multiple items that all are the same size, you can draw the marquee for one and then click the Copies the selected marquee button to duplicate the marquee and drag it over another item. The button looks like two overlapping squares.

Learn about creating a PDF file from your scans.