Anyone that have any proposal how to make long grass so it's looking natural ? What to use? Or is it something out there to buy ? Thankful for any help

Hello Hakan! I know there are a bunch of solutions to this need. It slightly depends on what you are trying to make, long clumps of grass or a very tall grass field.

My favorite product at the moment is Woodland Scenics static grass. It's very straight and works for covering large areas. For clumps you can also use Woodland Scenics field grass which you apply manually. Both work well and create a great level of realism at several scales.

I have also seen people use the ends or cheap paint brushes to create grass, but this tends to be a little unrealistic.

True on the paint brushes. But I have used the cheaper Chinese made wooden handled brushes They work. Just remember to make the ends at different legnths. They go for about 1 dollar for each--I get them at Ace Hardware.

I use the cheapo brush method too-- but I buy my brushes in a packet of "natural" colored horsehair brushes from Michael's for about $3.99 for 5-- and really, they are so lousy for painting, all you can use them for is long grass! I drill a bunch of small holes in the area I want the grass in (in a plywood or hardwood base that has been plastered for "terrain" (my favorite material is Durhams Water putty over foam). I then plant the "grass" that's been cut at various lengths. Afterwards, I can airbrush the "blades" whatever color suits me. I sometimes mix Woodland Scenics long grass into the bunch, to give some variety to the width of the "grass leaves". However. I find the Woodland Scenics" stuff looks more like hair than grass.
VR, Russ

If you want to use natural stuff, this wild grass grows along the sides of highways everywhere, and some unused fields are covered with it:
https://www.alamy.com/stock-photo-wild-grass-field-in-late-summer-31292742.html
The tops of the stalks have a head composed of hundreds (maybe thousands) of fibres ending in a little pod - looking much like a miniature of the entire plant.

Check out fake fur from your local craft or fabric store. It’s long and fine so it can be trimmed to length, and died to the color you want with acrylics.

Thanks all for the tips, will look for it.

There are Shep Paine's old standbys. unraveled sisal string, and crepe hair, (sold in make-up stores that cater to actors--it's used to make false beards and such). The blond shades make good dry grass, and you can also paint it. Both the string and the crepe hair need to be unraveled, wet a little, and stretched out straight as they dry. Then cut to length, and "plant" your tall grass in predrilled holes with a little white glue.