diff --git a/src/net/torvald/btex/BTeXDocument.kt b/src/net/torvald/btex/BTeXDocument.kt
index eb203a4a4..b74347758 100644
--- a/src/net/torvald/btex/BTeXDocument.kt
+++ b/src/net/torvald/btex/BTeXDocument.kt
@@ -8,6 +8,7 @@ import com.badlogic.gdx.graphics.g2d.TextureRegion
 import com.badlogic.gdx.utils.Disposable
 import net.torvald.terrarum.FlippingSpriteBatch
 import net.torvald.terrarum.ceilToInt
+import net.torvald.terrarum.concurrent.ThreadExecutor
 import net.torvald.terrarum.imagefont.TinyAlphNum
 import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.archivers.ClusteredFormatDOM
 import net.torvald.terrarum.modulecomputers.virtualcomputer.tvd.archivers.Clustfile
@@ -21,6 +22,7 @@ import net.torvald.terrarumsansbitmap.gdx.CodepointSequence
 import net.torvald.terrarumsansbitmap.gdx.TerrarumSansBitmap
 import java.io.File
 import java.io.RandomAccessFile
+import java.util.concurrent.Callable
 import java.util.zip.Deflater
 
 /**
@@ -161,14 +163,35 @@ class BTeXDocument : Disposable {
             pageTextures = Array(pages.size) { null }
             pagePixmaps = Array(pages.size) { null }
 
-            pages.forEachIndexed { pageNum, page ->
-                val pixmap = Pixmap(pageDimensionWidth, pageDimensionHeight, Pixmap.Format.RGBA8888).also {
-                    it.blending = Pixmap.Blending.SourceOver
-                    it.filter = Pixmap.Filter.NearestNeighbour
+            if (!multithread) {
+                pages.forEachIndexed { pageNum, page ->
+                    val pixmap = Pixmap(pageDimensionWidth, pageDimensionHeight, Pixmap.Format.RGBA8888).also {
+                        it.blending = Pixmap.Blending.SourceOver
+                        it.filter = Pixmap.Filter.NearestNeighbour
+                    }
+                    page.renderToPixmap(pixmap, 0, 0, pageMarginH, pageMarginV)
+                    printPageNumber(pixmap, pageNum, 0, 0)
+                    pagePixmaps[pageNum] = pixmap
+                }
+            }
+            else {
+                val jobs = pages.indices.map { pageNum -> Callable {
+                    val page = pages[pageNum]
+                    val pixmap = Pixmap(pageDimensionWidth, pageDimensionHeight, Pixmap.Format.RGBA8888).also {
+                        it.blending = Pixmap.Blending.SourceOver
+                        it.filter = Pixmap.Filter.NearestNeighbour
+                    }
+                    page.renderToPixmap(pixmap, 0, 0, pageMarginH, pageMarginV)
+                    printPageNumber(pixmap, pageNum, 0, 0)
+                    pagePixmaps[pageNum] = pixmap
+                } }
+
+                // my experiment tells 4, 8, 16, 32 threads all perform the same
+                ThreadExecutor(Runtime.getRuntime().availableProcessors().div(2).coerceIn(1..4)).also {
+                    it.renew()
+                    it.submitAll(jobs)
+                    it.join()
                 }
-                page.renderToPixmap(pixmap, 0, 0, pageMarginH, pageMarginV)
-                printPageNumber(pixmap, pageNum, 0, 0)
-                pagePixmaps[pageNum] = pixmap
             }
 
             isFinalised = true
diff --git a/src/net/torvald/terrarum/tests/BTeXTest.kt b/src/net/torvald/terrarum/tests/BTeXTest.kt
index 557877ba0..c2a327036 100644
--- a/src/net/torvald/terrarum/tests/BTeXTest.kt
+++ b/src/net/torvald/terrarum/tests/BTeXTest.kt
@@ -26,9 +26,9 @@ import kotlin.system.measureTimeMillis
  */
 class BTeXTest : ApplicationAdapter() {
 
-    val filePath = "btex_ko.xml"
+//    val filePath = "btex_ko.xml"
 //    val filePath = "test.xml"
-//    val filePath = "literature/en/daniel_defoe_robinson_crusoe.btxbook"
+    val filePath = "literature/en/daniel_defoe_robinson_crusoe.xml"
 //    val filePath = "literature/ruRU/anton_chekhov_palata_no_6.xml"
 //    val filePath = "literature/koKR/yisang_nalgae.btxbook"
 
@@ -72,7 +72,7 @@ class BTeXTest : ApplicationAdapter() {
                 }
 
                 measureTimeMillis {
-                    document.finalise()
+                    document.finalise(true)
                 }.also {
                     println("Time spent on finalising [ms]: $it")
                 }
@@ -103,7 +103,7 @@ class BTeXTest : ApplicationAdapter() {
         gdxClearAndEnableBlend(.063f, .070f, .086f, 1f)
 
         if (::document.isInitialized) {
-            if (document.isFinalised) {
+            if (document.isFinalised || document.fromArchive) {
                 val drawX = (1280 - (pageGap + document.pageDimensionWidth * 2)) / 2
                 val drawY = 24