Trying to post attachment..

Just wondered if anyone can help me. I am trying to attach an infographic to a new post (marketplace). The Image when opened in paint etc is around 1000px wide. Yet when I upload it onto here it displays as a tiny thumbnail like 150px wide??

Thanks in advance

Have you tried uploading it to something like imgur and then posting the code? That always works for me.

There are options to display it as full size, default shows thumbnail.