Contrary to appearances, new, just purchased nibs are not immediately ready for use. Why? Because they are covered with a waterproof chemical substance, which, of course, protects the nib during storage, but also hinders the proper flow of ink when writing.
Fortunately, getting rid of this chemical coating is very easy. All you need is:
• an old soft toothbrush,
• toothpaste or washing up liquid,
Apply a little toothpaste or dishwashing liquid to the brush, clean the nib well on both sides, and then wash it underwater and dry with a cotton cloth. The nib prepared in this way is suitable for mounting in the pen holder.
If you notice that despite this procedure the ink does not flow evenly from the nib, thoroughly clean it again in the same way, but rub it a little harder.
There is another method to get rid of the chemical coating from the new nib. It involves sunbathing. If you feel like trying this way, here are some tips: put the nib on the flame for a moment, then wash it underwater and dry it.
Personally, I only use the toothbrush method, but I described both ways so that you can choose the one that suits you better.