CAM350, Camtastic in Altium, gerber tool in ORCAD - all they open gerber files. So, if your files are really gerber files they should be opened there. BTW, which program generated these files? Select File - Plot from the menu to open the gerber generation tool. At the top of the pop-up window, you’ll see the folder location for your files, click browse. Make sure you’re in your project directory. Make a new folder called Gerbers, select it and click select folder. DesignSpark PCB provides a 'Manufacturing Plots' feature to allow you to produce Gerber files and use any board manufacturer you wish. Before producing the Gerber files ensure you have completed all the design checks of your PCB layout to ensure you do not have errors or unexpected cost penalties from selecting nonstandard track widths or spacing or other premium features.

Generate Drill and Gerber Files

Select File -> Plot from the menu to open the gerber generation tool.

Gerber Pcb Software Free

In general, there are 8x layers you need to have a PCB fabricated:

Top Copper (F.Cu)+ Soldermask (F.Mask) + Silkscreen (F.SilkS)
Bottom Copper (B.Cu) + Soldermask (B.Mask) + Silkscreen (B.SilkS)
Board outline (Edge.Cuts)
Drill file

In the Plot window with the Plot format set for Gerber, be sure these Layers are checked:

If you don't know which layers, please check all layers, JLCPCB will help you to use the right layers. Click ‘Plot’ to generate the gerber files for the layers.

Pcb Artist Gerber Files

Don't forget to Generate the Drill Files. Click on ‘Generate Drill File’ button. You can use the defaults here as well. Check the 'Merge PTH and NPTH holes into one file' box. For now just click ‘Drill File’ or press ‘enter’ to generate the drill file. Use the same output folder as for the gerbers, which should be the default.

Gerber Pcb Design

Check the Gerber files in GerbView

Next, click ‘Close’to exit the Drill and Plot windows. All of the files should have appeared in your gerbers folder. KiCAD comes with a gerber viewer called GerbView, you can open the “GerbView” and check what your board looks like before sending it to manufacturer.

For more details, please see this video tutorial of generating Gerber files for manufacturing in KiCad.
For Kicad 5.1.5, please check this tutorial.
If everything looks OK, select all of the files, zip them up, and upload the zip file to JLCPCB order page.

How To Open Pcb Gerber File