When it comes to embroidery puff, the needle size you choose will depend on the type of fabric you are embroidering on and the thickness of the foam or padding that you are using for the puff effect. Generally, a larger needle size is recommended to accommodate the thickness of the foam or padding.
A needle size of 90/14 or 100/16 is commonly used for embroidery puff. These larger needle sizes allow for the thread to pass through the foam or padding and the fabric without breaking or causing damage to the needle or the machine.
It is important to note that the type of needle you choose will also depend on the type of thread you are using, so it's always a good idea to consult the manufacturer's recommendations for the best needle and thread combinations for your particular project. Additionally, it's a good idea to test out different needle sizes and types on scrap fabric before embroidering on your final project to ensure the best results.