diff --git a/src/simulation/Simulation.cpp b/src/simulation/Simulation.cpp
index b1040f7d9..537d6fd4b 100644
--- a/src/simulation/Simulation.cpp
+++ b/src/simulation/Simulation.cpp
@@ -1094,6 +1094,10 @@ int Simulation::eval_move(int pt, int nx, int ny, unsigned *rr) const
 					return 0;
 			}
 			break;
+		case PT_PAPR:
+			// May allow PAPR to block particles when marked? Or would that be too contrived?
+			result = 2;
+			break;
 		default:
 			// This should never happen
 			// If it were to happen, try_move would interpret a 3 as a 1
diff --git a/src/simulation/SimulationData.cpp b/src/simulation/SimulationData.cpp
index 1e101a851..d1a886164 100644
--- a/src/simulation/SimulationData.cpp
+++ b/src/simulation/SimulationData.cpp
@@ -185,6 +185,10 @@ void SimulationData::init_can_move()
 		//SAWD cannot be displaced by other powders
 		if (elements[movingType].Properties & TYPE_PART)
 			can_move[movingType][PT_SAWD] = 0;
+
+		// Let most non-solids pass through PAPR
+        if (elements[movingType].Properties & (TYPE_GAS | TYPE_PART | TYPE_LIQUID))
+            can_move[movingType][PT_PAPR] = 2;
 	}
 	//a list of lots of things PHOT can move through
 	// TODO: replace with property
diff --git a/src/simulation/elements/PAPR.cpp b/src/simulation/elements/PAPR.cpp
index 4a9892f5d..1083418ee 100644
--- a/src/simulation/elements/PAPR.cpp
+++ b/src/simulation/elements/PAPR.cpp
@@ -8,8 +8,8 @@ static int graphics(GRAPHICS_FUNC_ARGS);
 // Additionally, it can be read and written to by ARAY.
 
 // Property usage:
-// life: Temporary read/write state for ARAY interaction
-// tmp: Written color value. If dcolour is not black, it gets copied here. 1 bit alpha
+// life: Written color value. If dcolour is not black, it gets copied here. 1 bit alpha
+// tmp: Temporary read/write state for ARAY interaction
 // tmp2: Singe level
 
 void Element::Element_PAPR()
@@ -58,6 +58,7 @@ void Element::Element_PAPR()
 
 static int update(UPDATE_FUNC_ARGS)
 {
+	// Char when above burning temperature
 	if (parts[i].temp > 450 && parts[i].temp >= parts[i].tmp2)
 	{
 		parts[i].tmp2 = (int)parts[i].temp;
@@ -73,7 +74,6 @@ static int update(UPDATE_FUNC_ARGS)
 			if (np >= 0)
 			{
 				parts[np].life = 70;
-				// parts[np].temp = parts[i].temp;
 			}
 		}
 	}
@@ -82,6 +82,7 @@ static int update(UPDATE_FUNC_ARGS)
 
 static int graphics(GRAPHICS_FUNC_ARGS)
 {
+	// Darken when burnt
 	float maxtemp = std::max((float)cpart->tmp2, cpart->temp);
 	if (maxtemp > 450)
 	{