Add materials

README.md

@@ -99,6 +99,44 @@ In terms of software if the chip has a linux mainline support then the path of l
 
 The closest comparable project would be [OLIMEX Teres-A64](https://www.olimex.com/Products/DIY-Laptop) which kit costs 240 EUR, the cost of the mainboard from first hand is 80 EUR (https://www.olimex.com/Products/DIY-Laptop/SPARE-PARTS/TERES-PCB1-A64/open-source-hardware) and fabricating board with dimensions 113.5x89mm of 6 layers costs around 68~280 EUR for 5 boards without components.
 
+### More options for PCB Materials
+
+This solution also allows us to use different materials economically for the platform board.
+
+#### FR4
+
+Around 5~20 EUR for 1 or 2 layers
+
+Around 20~70 EUR for 3 or 4 layers
+
+#### Copper Core PCBs
+
+Around 60 EUR if kept at 1 layer
+
+#### Rogers
+
+Around 100 EUR if kept at 2 layers
+
+#### PTFE Teflon
+
+Around 50 EUR if kept at 2 layers
+
+#### Flex
+
+Around 30 EUR for 2 layers
+
+Around 200 EUR for 3 and 4 layers
+
+Could be more economical and ecological than the common FR4 and probably better option for prototyping, but use in production and mission critical environment is discouraged (could be placed on a solid material?)
+
+#### Ridgit flex
+
+Cost and usage unknown
+
+#### Shengul SH260
+
+Cost and usage unknown
+
 ### Additional Notes
 
 Originally discussed in https://git.dotya.ml/kreyren/kreyren/issues/75