EVERYTHING OLD IS NEW AGAIN
My first real graphics computer was an Amiga 2000, I had it supercharged with 8 whole megabytes, and a syquest 40mb removable hd cartridge. 256 colour animations were cutting edge and I really didn’t understand why I’d ever need a second 40mb hd. Fast forward 3 decades and while everything else has changed, pixel art is undergoing a renaissance and gifs are in common use, especially in EDMs and email marketing campaigns.
This page is a general information dump on gifs, what they are, what they’re useful for, and how to use them effectively. It’s based on my experience as an animator and designer.
The Graphics Interchange Format (GIF) displays an eight bit indexed image format with limited compression, its two main advantages are the format’s ability to store animation and its compatability, especially where email is concerned. GIFs are currently the only animated format to play across email clients, although file sizes should be restricted to avoid tripping SPAM filters.
In most cases gif files will play as the file loads. They can be set to play a set number of times, including once, or in an infinite loop. Generally an infinite loop with a pause at key points is the ideal. In those cases where the GIF doesn’t play automatically, usually older versions of Outlook, the first frame is displayed. Care should be taken to include essential information on this frame, which often means the loop starting at a midway or end point before travelling to the beginning and starting again.
GIF animation compression is based on three main factors, The number of colours, the dithering and transition between these colours and the change of individual pixels over time. The ideal design is a GIF with a small number of flat colours, eg 16, which loops over time.
Images which draw on are an ideal use of gif compression as the animation size can be compressed to the size of two images. The 256 colour limitation is also reduced as two and four colours are often enough for this type of image. Gifs have 1 bit(on-off)transparency allowing then to overlay background images. For Edms this requires a contrasting bg colour for Outlook clients.
FLAT COLOUR IMAGES WITH LIMITED ANIMATION
For flat colour images with looping elements GIFS provide motion to draw the eye and add interest. It could be a character talking, text animating or limited animation.
We’ve all seen them, short snippets of video compressed as gifs. They can be amusing, but they also tend to be too large for EDM’s due to our next point.
GIFS AND SPAM FILTERS
The last time I reviewed spam filters, there were two main points at which the size of graphics impacted on the EDM. Emails with graphics above 150kb are more likely to be picked up as spam, and with graphics above 600kb are significantly more likely to wind up in the spam folder. Research was carried out in 2017, so it is possible that the numbers have shifted since.
GIF RESOLUTION AND OPTIMISATION
I think resolutions should be a factor of 8(possible 16). In the case of a 600×430 gif which had a black line artifact along the bottom(430) edge, the problem was solved by setting the y dimension to 432(which is divisible by 8).
Output should ideally be set to 16 (or less) colours with dithering and transparency turned off and frame differencing turned on. While this creates a small file it can be reduced further using gif optimizer at www.gifgifs.com/optimizer/ . The default setting of light compression works well.