If you purchase or download images online, you would have encountered some of the different file formats they are saved in. There are PDF, JPG, TIFF and the list goes on! I try to explain the most commonly used file formats here. *My posts contains affiliate links.
Here are the most common file formats:
Raster images are made from a fixed grid of pixels, they experience a loss of quality (resolution) whenever resized, especially when you’re trying to make them bigger (scale them up).
Typically used for high qualily photography and low res online use. Does not support transparency. Not recommended for print use
TIFF is the best and only choice for professionals when images are intended for print. Its ability to read CMYK and YcbCr color, plus its ability to store such high pixel intensity makes it the only choice for designers, photographers and publishers.
GIF files can be saved with a maximum of 256 colours. This makes it a poor format for photographic images. Gifs are best used for single colour images. They can be animated, which is another reason they became so successful. Most animated banner ads are GIFs. GIFs also supports transparency, this allows the background colours of the web page to show through the image.
This file format was designed for transferring images on the Internet, not for professional-quality printing. PNG is the better quality version of Gif images. It is also perfect for saving transparencies - an image or logo without a background. They cannot be animated.
Vectors can be scaled up infinitely and still stay crisp and clear. They are typically used to create illustrations, text and logos, but they cannot handle complex images like photographs. At some point, all vector graphics must be rasterized in order to be displayed on digital monitors or when printed. Plotters are printers that use vector data rather than pixel data to draw graphics/cut files (for vinyl etc.).
SVG stands for "Scalable Vector Graphic". This is the new format used for animations & other graphic content on mobile phones and PDA´s.
AI (Adobe Illustrator Artwork)
This is Adobe Illustrator’s native format. It is the working, layered, vector file.
The CDR file format is recognized by the majority of image editing programs.
- DXF is an AutoCAD data file format for enabling data interoperability between AutoCAD and other programs.
These are formats that could contain both pixel and vector data
Used for logos and illustrations as a vector. Can be scaled to any size without losing quality. Supports transparency and is perfect for large format printing. EPS files can be opened in many illustration applications such as Adobe Illustrator or CorelDRAW.
PDF represents the printed paper versions of your document exactly - what you see is what you get. It cannot be edited without the proper software - which makes it ideal to send out to clients, or offer as downloads. PDF files can contain both vector and raster images. They can also contain interactive elements, like form fields and hyperlinks. It is used in professional printing worldwide.
There are a loads more file formats, but these are the only ones you will need for blogs, crafts or printed designs (like book covers, pamphlets etc). If you do want to know about other formats- I found pretty comprehensive lists on Zamzar and Online-convert.
Which one of these file formats should you use?
This will depend on what you want to use it for.
File formats for use in print or on the web differs vastly.
On the web, you want the highest quality image in the smallest possible file size - this is known as an optimised image. You should consider file size carefully and it is best to use images smaller than 1MB (megabyte) on the web. This helps with page loading times and bandwidth. The best file formats for web images are .jpg, .png and .gif.
Basically an image is a grid of pixels (called a raster). A pixel is the smallest single component of a digital image. In short - the more pixels, the higher the resolution (quality) of an image.
For print, you need very specific resolutions, regardless of your file size. Higher dots per inch (dpi) means higher resolution. Resolution is not “size”, but it is often confused with it because higher resolution images are usually bigger. For print files 300dpi is standard, sometimes 150 is acceptable, but never lower than that. For printing .tiff and .pdf and some large .jpg files are the best choices for file formats. Here file size is important directly opposite to web, the bigger the file size, the better for printing! A few MB is better than a few KB (kilobyte)!
If you want to edit a file,you need the "working" file format, this can include layers, editable text, filters/effects etc. and will allow you to easily change the font, colours, images and more. This file format will differ, depending on the software you want to use it in. For editing in Photoshop, you need a .psd file format, for Illustrator you need .ai or .eps and so on - each software has it's own unique file format.
For use with your vinyl cutters (plotters), like the Silhouette Cameo or Cricut machines, you usually need .dxf or .svg file formats. The software can also import a variety of other common image file types (JPG, PNG, BMP, GIF, and TIF files), but you will need to Trace the image using an auto-trace function to create cut lines and an .svg file.
A .pdf file can be opened in more than one software program, but it is not the "working" file, rather a flat image that you can edit with certain software only. Perfect if you need to send a sample graphic to a client.
I hope these explanations makes working with images a bit clearer to you!