‍I do not know what they are called but I am going to make some for us

and you can to if you want to...

we will call them plates. because it is only to be a design a clear design on a frame..

ok I am starting by opening up a 800 by 250...

going to go the the paintbrush and paint it white

now I am going to go to selections

tool options, mine is on the bottom right

click on it and lets say lets us use circles

‍

go to the 800 by 250 and lets start close to the corner top right

and make a circle

now move the mouse over it and click on it

move the inner circle somewhere away from the frame

we do not need this...

now select none

should look like this

now we can make as many as we like

and when you are done be sure to click

select

select none

merge visible