What is the name??

This is going to sound so stupid but I swear I've looked online for "cotton blanket", "baby blanket", "swaddle blanket" and many other abbreviations of the term but what I want doesn't seem to appear! Online shopping is the worst! I basically want a simple thin baby blanket (not a muslin blanket, or anything knitted) to swaddle my baby in for his first picture.. does anyone know what I should be searching online for?? Something like the below pic