Will I see any difference between 0.1 and 0.02 resolution?

[levalencia]

If I am looking to make a business selling 3d models, 3d Selfies, 3d customized printed parts for example; iphone holders, keychains and that kind of stuff. Will my eyes be able to see any difference in the result if I buy a printer with 20 microns resolutions vs 100 microns resolution?

I heard that a human hair is about 45-75 microns, so I doubt that I can see any diff

[LambdaFF]

The best you can do at that point : make a design. Then go to 3D Hubs and order a print from one of the printers you have in mind and see the result for yourself.

We can talk about it for ages and you still won't know.

Once again, there have been several threads with this kind of topic : starting a business; whether FDM machines are adapted to a business and which kind of business, .... You should look them up.

[iDig3Dprinting]

The best you can do at that point : make a design. Then go to 3D Hubs and order a print from one of the printers you have in mind and see the result for yourself.

This is probably the Best idea.