Using checkboxes on submission page to create custom search fields

I am creating a Print Shop Directory and I am using check boxes on my submission page to allow print shops to choose multiple options, so that my visitors can really narrow down their search.

Example: print shops can offer an array of paper, 14pt thick, 16 really thick, 32 super thick.

I want print shops to check all paper types that they offer, so that site visitors can sort through shops that only offer the paper they are looking for.

Okay, now my problem.
I am creating Custom Advance search fields based on the options (checkboxes) selected on the submission page, but when I test the search it doesn’t work.

I did a test and changed the submission page options to “selection” instead of check boxes and it worked fine.

Is it even possible to do what I am trying to do? can anyone suggest a workaround or solution?

businesscardprintingservices.net/dir/

Thanks in advance to any help.

Ps I am going insane… 2:23am

Pps There isn’t parent forum selection for the Responsive DP.