Just a suggestion- i use pastels for weathering as well, and I used to use those standard fat Q tips which tend to get big and fuzzy after a while and makes it very hard for fine detailed streaks.
I suggest picking up a super fine tip brush from the art store.
Make sure the tip is extremely short.
The longer the tip the harder it will be to maintain tension for laying down pastels.
I have about 8 different brushes for weathering.
Some are soft tipped for laying on really soft subtle streaks, some are harder tipped for laying down darker streaks.
Different shape tips also help as well.
If you want to get really dark pinpoint blast marks, then pickup the small modeling Qtips.
They are extremely dense and dont get fuzzy.
Just dip the tip onto the pastel dust then press the tip onto the model, turn the q-tip a few times (like youre trying to drill into the model) then pull away in the direction you want the streak.
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