Is there a way to replicate shuttle tiles? I have tried spraying through screen but can seem to get it butted up against the surface to work.
The relief detail isn’t molded into the kit surface?
I personally have not tried this, but I have heard that if you stretch a pair of pantyhose over the area to be painted then paint over the pantyhose, you will get a tile like look
Please test on something first … I may be forgetting something…
There are tile decals available in 1/72, 1/100 and 1/144 scale that look very convincing.
They can usually be found on eBay for a reasonable amount. Here’s a link to a set in 1/144 scale:
I found a build by Phil Smith on super detailing the 1/72 orbiter, he used styrene sheets, scored them, then cut them to replicate tiles. I did this and it came out fantastic. He also used medical tape to simulate the thermal blankets, and I stole that idea as well 
I can’t find his original webpage, but a google search can provide you with some info and some that followed his lead.
Found a link to Phil’s article, it is now on yumpu (is that like the way back machine?)
https://www.yumpu.com/en/document/read/3645330/1-72-space-shuttle-discovery-astrazoic
In most scales I dont think the relief texture of the tiles would show through. Maaaybe in 72nd. I’m working on a 1/144 and I think that even the slight texture of the decals is overdoing it a bit, but I do think they are the best bet. One could even paint on top of the decals to show streaking, etc. I saw Discovery at the Udvar-Hazy Center and the tiled surface is surprisingly smooth. What poses a bigger challenge to me is the blankets. They have a very distinct texture and pattern but again, replicating in 1/144 is difficult. In 72nd I’ve considered things like medical tape, but at this time I have no plans to build a 1/72 scale orbiter.