This kind of image probably must be rasterized before printing onto a cloth. It's too complex to be silk screened or plotted.
Obviously you want the cloth to be visible just like the blue was in your first image. The clouds are wanted as partially transparent white on the canvas.
Ask, does the print process accept partial transparency to make the cloth partially visible and what is the right file format to deliver the image with transparency
Let's assume the right format is a PNG24 with alpha. Be sure that you also know the pixel dimensions.
=> Make a full white image with the wanted pixel dimensions. Extend the black to cover fully the white area. Use your black-white shape as the opacity mask or alpha channel. Export as PNG with no background.
Chek the transparency in a raster image editor before sending to the printer
It's possible that you must use some own half-toning to create the illusion of the transparency. The printer surely tells, if you ask.
NOTE: Nothing replaces the asking, so at first contact to the printer and get the proper data.
How to make a file
If you want to make a file in Photoshop, you probably do not want to delete the black areas and print the rest, because the non-whiteness should be partially transparent white. No grey areas are wanted. This is true assuming your blue image to be the wanted result on blue canvas.
Make an empty RGB image with the wanted pixel dimensions
Place your shapes (sorry, I have only the screenshot with your mesh) as pixels, fill the empty area with black. Now you have:
- Make a white layer, copy the BW layer to the layer mask of the white layer, create below all a colored test layer which simulates the canvas. Hide the original BW layer. Then you have:
You might want to edit the edges and the general contrast of the transparency. You can brush a little more black or white to the mask of the white layer. You can also select the layer mask icon and adjust the curves. That affects radically on the steepness of the transparency:
When you are happy, hide all other layers but the white one with the layer mask and save as PNG.
Test the transparency opening the PNG.
NOTE: the need of the PNG is not sure before asking. As well the printer can want a PDF, SVG or an Ai file.
In vector domain you also should get rid of the black. Unfortunately I haven't the vector version and there are nothing visible of the used blending and transparency modes so I cannot give any receipe.