You need to combine 10 to form a random chapter.
However, if you’re up for an adventure and you’d like to try your luck, this is how you can get them.
Only crown store exclusive motifs cannot be posted to guild stores, others can usually be found and that’s how I learned pretty much all of them. But remember, you can (almost) always buy eso motifs in guild stores in case that you don’t have access to a certain DLC zone or do not want to spend time farming them. Some of them are very easy to get, some are not. This guide will teach you how to get (at the time of writing) ALL motifs in Elder Scrolls Online.