Available file formats: JPEG and TIFF:
The downloadable images are made available as high resolution scans in the JEPG format (.jpg), or in the TIFF format (Tagged Image File Format). JPEG is the most popular and compatible image format and has become the standard file format for most digital cameras. It is also supported by most of the popular imaging software. JPEG uses lossy compression, meaning that some image data is lost when the file is compressed. JPEG is great for creating smaller file sizes for uploading on the Internet, or for use with e-mail. If you are an average computer user JPEG format will cover your needs. High quality JPEG images provide you with images suitable for printing and for using in your private publications.
The TIFF format is the standard for most commercial and professional printing needs. TIFF files are very large in size compared to JPEGs because no compression is used. JPEG files typically range from 1:5 to 1:25 the size of TIFF files. Because of this they are not very well suited for delivery via downloads or e-mail. Large files like that needs to be zipped, and are best suited for delivery on a CD. If you need the absolute best quality image for professional use then TIFF format will serve you well.
Quality - Resolution and DPI :
When scanning the original images to digital format DPI is used to adjust the amount of detail of the scan. The DPI setting of the scanner relates to the final pixel size of the scanned image. The DPI in the digital image files refers to the physical size of an image when it is reproduced as a real physical entity, for example printed onto paper, or displayed on a monitor. An image measuring 5 x 4 inches scanned at 300 dpi will give a digital image 1500 x 1200 pixels in size (5 x 300 = 1500 and 4 x 300 = 1200). Best results for printing a 1:1 size copy will be achieved with files scanned with 300 dpi. If you want to make enlargements you get better results with a 600 dpi or 1200 dpi scan.
The average size of the original postcard images we offer is 5.5 x 3.4 inches (14 cm x 6.6 cm). When scanned with 300 dpi the image will be approximately 1600 x 1000 pixels in size (depending on the exact size and proportion of the original). As most of our images are scanned from old postcards (or postcard size photographs if nothing else is specified), a 300 dpi scan will print a 1:1 copy (5.5 x 3.4 inches, 300 dpi output) without loss of quality. You can also print a 2:1 copy (11 x 6.4 inches, 150 dpi output) without noticing any significant loss of quality.
You should also note that many of the images are copied from originals which are very old, and the quality of the digital copies will be limited by the quality of the original. The images you purchase are without the watermarks. If you have any questions regarding the image file formats and quality, please contact us.