High resolution image needed

I like to keep at least one high resolution image of every variety for comparison. I have almost 100,000 low- and mid-resolution images that I have collected from contributions, auctions, dealers and eBay. However, I often need to examine details that are otherwise invisible because of quality. So I always ask for high-resolution images from collectors, dealers and correspondents.

How good do images need to be? A good rule-of-thumb is that scans should be good enough to read printers' names. I have created several web pages dedicated strictly to how to scan stocks and bonds.

Scanning suggestions.

• Scan in full color
• Scan against a white background
• Scan at 300 pixels (aka dots) per inch
• No reduction (see note)
• Scan entire certificates (full borders)

Do NOT scan

• stubs
• coupons
• backs

Significant signatures

• Scan at 600 dpi with some extra space

Hints for scanning certificates too large for your scanner

• Scan in two or more pieces
• Always keep the same orientation for all the pieces (i.e. keep the top facing the same direction)
• Hold down tight to the glass
• Scan pieces with at least 1.5" of overlap
• Remove the cover of your scanner for delicate certificates
• Send the pieces (I will patch together)
• Keep certificates away from edges of scanner if possible (i.e. scan in the middle of the glass)
• Read Scanning Large Certificates for more information.

Save format

• JPG or JPEG. Save at medium high level quality. No need for highest quality.
• TIFs and PNGs are okay but create MUCH larger files.

How to send

• If sending a few JPGs, send as e-mail attachments (zipping does NOT compress JPGs.)
• If sending TIFs or several JPGs, send via WeTransfer.com (it's free) or "Dropbox Transfer." (I do NOT use Dropbox.)

Note.

Many people think they are sending acceptable images, when in fact they are not. This is usually because they reduce their images while scanning.

Let me illustrate what happens when you reduce images while you scan.

Imagine your stock certificate is 10" wide and you scan at 150 dpi. The resulting image will be be 1,500 pixels wide.

However, if you reduce you certificate 50% during scanning, your resulting image will be only 5" wide. 5" x 150 dpi = only 750 pixels. I might be able to use such an image, but it will look scuzzy. You may think you are saving file space, but you are actually decreasing resolution.