https://github.com/plotly/image-exporter/issues/65#issuecomment-380532988

Author: JamesCropcho

src/app/runner/coerce-opts.js

@@ -15,7 +15,7 @@ function coerceOpts (_opts = {}) {
   const opts = {}
 
   opts.debug = !!_opts.debug
-  opts._browserWindowOpts = {}
+  opts._browserWindowOpts = { show: false }
 
   opts.parallelLimit = isPositiveNumeric(_opts.parallelLimit)
     ? Number(_opts.parallelLimit)

src/component/plotly-graph/render.js

@@ -154,7 +154,8 @@ function toPDF (imgData, imgOpts, bgColor) {
   return new Promise((resolve, reject) => {
     let win = remote.createBrowserWindow({
       width: wPx,
-      height: hPx
+      height: hPx,
+      show: false
     })
 
     win.on('closed', () => {