diff --git a/misc/sandbox/DT-testing-plotSPC.R b/misc/sandbox/DT-testing-plotSPC.R
new file mode 100644
index 000000000..934ed5554
--- /dev/null
+++ b/misc/sandbox/DT-testing-plotSPC.R
@@ -0,0 +1,49 @@
+library(aqp)
+library(soilDB)
+
+
+osds <- fetchOSD(c('leon', 'musick', 'clarksville', 'sierra', 'pardee', 'amador', 'lucy', 'dylan', 'tristan', 'pierre', 'drummer', 'zook'))
+
+# encode horizon boundarydistinctness via vertical offset
+osds$hd <- hzDistinctnessCodeToOffset(
+  osds$distinctness, 
+  codes=c('very abrupt', 'abrupt', 'clear', 'gradual', 'diffuse')
+)
+
+# encode horizon boundary topography via vertical offset
+osds$hzto <- hzTopographyCodeToOffset(
+  osds$topography, 
+  codes = c('smooth', 'wavy', 'irregular', 'broken')
+)
+
+# also encode horizon boundary topography las line type
+osds$hzto.lty <- hzTopographyCodeToLineType(
+  osds$topography,
+  codes = c('smooth', 'wavy', 'irregular', 'broken')
+)
+
+site(osds)$code <- 'OSD'
+
+osds$bnd.code <- sprintf(
+  "%s%s",
+  substr(osds$distinctness, 1, 1),
+  substr(osds$topography, 1, 1)
+)
+
+osds$bnd.code <- gsub('NANA', '', osds$bnd.code)
+
+# ok
+par(mar = c(0, 0, 0, 1), bg = 'black', fg = 'white')
+plotSPC(osds, width = 0.3, hz.distinctness.offset = 'hd', hz.topography.offset = 'hzto', cex.id = 0.66, cex.names = 0.66) 
+
+
+## DT testing
+
+library(data.table)
+aqp_df_class(osds) <- 'data.table'
+osds <- rebuildSPC(osds)
+
+plotSPC(osds)
+
+plotSPC(osds, width = 0.3, hz.distinctness.offset = 'hd', hz.topography.offset = 'hzto', cex.id = 0.66, cex.names = 0.66) 
+