i'm not sure what it's called officially, but we had to do these at art school ( in Italy) and they help you learn to understand your medium.
As watercolors are transparent, you can overlay them easily, but some colors are treacherous and will bleed no matter what.
two colors laid on top of each other might look completely different depending on which color is on top or at the bottom.
At school we were supposed to make a grid, but nowadays I just wing it. If i had made a
grid I would have known all the 36 Distress refills I have were not going to fit, I did switch to a smaller brush in an attempt to make it all fit, but I missed out on 3 colors, not the most important ones, so I'm fine with it (grey and black oh so maybe just 2 lol)
I did the same with my Talens ecoline I have 18 of the 48 colors in the range and I have 36 of the 60 Distress re-inkers.
It's important to use the re-iners, undiluted as that will give you the most true color.
I was pondering whilst doing this, that maybe the Distress markers or any other watercolor marker might also work and then you could use a ruler to make nice straight lines, if you're ocd like that, I'm not, that's why I just wing it lol....
It takes a lot of calculating and a lot more time to make the grid in pencil, but ofcourse it looks much neater and at school we had to, I hate have tos ;-)
Normally , like with the Talens I would go in rainbow order, but for the Distress inks I followed the color chart from their website. with 60 colors you need a big big square of paper!
this is an A3 size paper or 30x40cm and it only fit half of the re-inkers, so...beware before you begin.
If you can use a big flat brush, it makes it easier to go straight and you don;t have to dip your brush as often and you get the neatest line.
i think for the long side of the paper it took just1.5 drops of re-inker and one for the short side, not too much.
Some colors go further with the same drop as the flow better on the paper, you'll see some are dryer it seems. I think it has to do with the pigments.
You do one side first, I'd suggest the short side if you're winging it, if you measured it doesn't matter as you already know how it will fit.
let it dry completey, preferribly overnight or 24 hours if you can.
It must be completely dry before you add the crosslines.
I know Distress reactivates with water , or moisture, but I had little problems. I was quite surprised really.