Hello @Marco_Krieger and welcome to the forum 
It’s ok to post links here but as a new user you will be limited in how many links (and uploaded images) you can post.
As time goes by and you use the forum more, those limits will be lifted automatically.
You’re asking for help with a specific subject so I’ve changed the title and category of your topic to make it show that.
Maybe one day you can create a topic in the Resources: Brushes and Bundles category where you offer for download the oil painting fan brushes that you’ve made