diff --git a/notes/3D printing/Filament.md b/notes/3D printing/Filament.md
index 5377ce8..81bd5ce 100644
--- a/notes/3D printing/Filament.md	
+++ b/notes/3D printing/Filament.md	
@@ -23,4 +23,13 @@ The addition of metal particulate reduces the strength of the print and makes it
 ### Wood-filled PLA
 Wood-filled PLA is  comprised of sawdust, and PLA. Cheap wood-filled PLA looks brown and has no particular wood-like qualities, but higher quality WF-PLA has visible chips of wood. This impacts the print by giving it a wood-like texture and allowing you to use varnish on the print.
 
-WF-PLA is difficult to print with, it easily absorbs humidity and sputters from the nozzle. The resulting product is also weaker.
\ No newline at end of file
+WF-PLA is difficult to print with, it easily absorbs humidity and sputters from the nozzle. The resulting product is also weaker.
+
+### PLA Alloys
+This category of PLA is created by combining PLA with another plastic additive to change the properties of the resulting filament in some way.
+
+There are 3 primary categories of PLA alloys:
+1. "Tough" PLA
+Tough PLA is created by combining PLA with polybutylene terephthalate, or PBT. PBT is commonly used in keycaps for keyboards.
+
+Tough PLA prints and acts similarly to PLA, but it has higher temp
\ No newline at end of file