How to make stamps on ezgif
First you grab a gif you like:
Then go onto ibis paint X to find out the dimensions of the inside your stamp boarder.
The one I'm using is 93x50 so that's the dimensions we will resize the gif on ezgif.
Next you want to open up ezgif and resize your gif to the dimensions you just found on ibis.
Once your gif is resized you need to head onto 'crop' once on that tab you will need to click the big blue "extend canvas size" button
This is where the OP said we would need maths, but honestly just play around with the numbers you'll find the new dimensions easily enough, you can just drag the crop box too!
Once you have added that transparent area around your gif, you then need to select effects > more tools > add overlay
Then once here select your stamp boarder, and boom, stamp!
You can make these various sizes if you wanna play about with the dimensions yourself in ibis paint X like I did!!
It gets a bit tricky with the resizing process but once you get the hang of it it's worth it!!
Tagging and credits to the post I learned from below
