[cbhaunt]

Well after decade we finally are making our cemetery fence towers.
18"x18"x48", 1x2 frame on a 2x3 frame base. 1/2" blue foam covering it, 2" foam tops.
We have routed out blocks 12" long by 6" deep so there is only one vertical grout line per horizontal line.
I know, a pic would be easier ... Do not have one yet. Will do one Monday.

Anyhow, the question.
We have light grey paint for the towers that we want to use the pneumatic sprayer to apply it. But we want the grout lines to define the blocks, to be darker.

We are not artistic so even testing hasn't given a clear answer ...

So do we paint the grout lines black, then few days later spray the towers including the grout lines ? Maybe the black underneath will define them? Or...
Is it better to spray the towers then few days later use a brush, or airbrush, to paint the black grout lines? Or......
Some other technique?

We will be trying a black dry brush over parts of the towers.
There are 8 towers plus two 6' high plywood, not foam, gate towers that will eventually have an archway name, when we figure that out.

So......... Thoughts for the artistically challenged?

 

[RCIAG]

If you want the grout lines to stay black & you want to use a sprayer you'll have to go back over the grout lines with black with a brush.

 

[kittyvibe]

when I painted my house, the front is brick, we sprayed the grout color first then went in and painted the individual bricks. This worked better vs painting the bricks then going back to grout lines as the color of the original wall still shown through in some areas and having all that retouching was a pain in the butt.

found it much easier to just spray the grout color all over, paint the brick, then go back in as needed for grout lines. Though going back to grout lines should be minimal. remember too, with painting, usually you start back to front. so grout (back) to brick (front).

 

[McBernes]

This may have been suggested but, paint the whole thing the base color. Then go back with a darker color for the highlights including the grout. I've done marble and granite finishes on airbrush paintings and that is the general way I learned to do it. For example: to paint a granite finish spray a neutral grey, spray blotches of white and slightly darker greys, dip a toothbrush or wide paintrush with white and flick or rub your thumb over the bristles to create a spackled or stipled pattern. then do the same with black. Use some judgement when doing this, not too heavy in one spot or the other. It is a similar thing with marble, only you will be painting veins with darker and lighter greys, black and white. The idea is to overlap colors and spackles and thickness/thinness of veins to give the piece some dimension.

 

[Abunai]

This would be how I'd paint them:

Spray paint the entire column black.
When dry, use a dark gray paint to dry brush the "bricks".
When that's dry, use a third, light gray paint to dry bush highlights on top of the previous layer.
For aging/detailing, spray very watered down black, brown, and mossy green paint at the top and let it drip down.

Practice all of this on some scrap before you try it on the actual columns.

Post copious amounts of pictures.