Here's a handy 3-pack of 3cm x 7cm Proto-board PCBs in Adafruit Black. Both sides have a black silkscreen with some row/column markings. Note that these don't have any traces between the PCB holes, you would normally bend over a thru-hole lead to create connections. They're also good for just plain mechanical work because they are made of strong FR4 https://elecena.pl/product/17502816/universal-proto-board-pcbs-3cm-x-7cm-3-pack 2021-04-07 https://elecena.pl/product/17502816/universal-proto-board-pcbs-3cm-x-7cm-3-pack 2022-03-26