Disclaimer: this is not to undermine the silkscreen techs, your time and efforts is obviously appreciated in the area.
But if like me you have had ongoing issues trying to get your screen to expose or you have artwork but unsure how to get it onto a screen to start the print experimentation stage . You might be interested in checking out Printall https://static1.squarespace.com/static/54bf94a1e4b0d46731b918b9/t/58adc921f7e0ab695ad614f2/1487784226629/LSS+FRAMES+PRICELIST+2017.pdf
They have worked with top brands and services and really do have a wealth of knowledge and expertise on most things print and happy to give intensive over the phone advice.
The real reason I mention them is that they have a exposure/stencil service where you can take your screen, and art work and the will expose your screen so you can get on with the fun part of printing rather than trying to figure out why your 10 attempt at exposing didn’t work out.
To give a guide on price they will expose a A3 size screen with artwork on transparent film for £38.60 including VAT. If you require them to print out the art work it will be additional £23.
Hopefully that is helpful for someone.