Custom Paint - Workshop specials.

In our booth, we have silicone corks and bungs in various dimensions which are resistant to heat and chemicals and easy to clean. You can get these from home brewing beer sites and such... or I'm sure eBay will have them.

Anything with a thread can have a blank bolt popped in it as @Brommers has said. These can also double as additional handling points so you don't put your fingers in wet paint whilst you move the frame around as you paint... fwiw, if you aren't moving the fame around while you paint, you're doing it wrong!

A sacrificial seatpost with tape around it is great too.

Same for the BB... pop an old one in there in you have one.

Just dunk that stuff in paint thinner when you're done and wipe it clean with some scotchbrite.

We cut sheets of assorted sized vinyl circles on a daily basis with our plotter and then pop them over anything we need to cover, flash them with a heat gun and then paint. This is often better than using bolts, which can sometimes get in the way of even coverage, especially in a fade for example.

In some cases, because of colour combinations, or specific product nuances, masking or blanking a thread just doesn't work, so you can simply ignore that stage, and rely on cutting the thread clean afterwards.

It's also worth knowing that sometimes it's simply much more practical, and gives a better result if you paint over something and then sand the paint off afterwards... lots of builders have stainless elements in awkward shapes and masking can be a big time investment so it can simply be easier to primer, then sand the primer off, then base and sand, then clear and sand. Here's an example.

Same is true of stainless bottle bosses or track ends... if it doesn't need paint, don't put paint on it because the alternative is that you'll bind and grind the paint off when you fit your bottle cages or put the rear wheel in etc.

I'd avoid using cotton buds completely... this is poor DIY practice, the fibres from the them can get in the finish, and they can also be too absorbent and draw product away from where it needs to sit.

I'd also swerve any kind of bing bag/clingflim affair that I've seen people get involved with online... paint can dry on the surface of these and then as soon as you remove it, crinkled up crumbs of colour land unevenly in your work.

If you're plotting graphics, a rolled up piece of your backing sheet can be used on a BB.

And if you're using masking tapes, just make sure you use a tape designed for an edge if you want a clean edge.

And if you have a nice bike with an internal headset, be mindful that some masking tapes can leave a gluey residue so be prepared to remove this with a suitable solvent, or choose your tape carefully.