In most cases, Yes, the pen or pencil should be finished and assembled before being engraved.  We can engrave pen and pencil barrels prior to assembly, but you risk damaging the engraving if pressure on the barrel is applied over the engraved area.

Finishing the pen after engraving can be a problem.  Pen barrels are very thin.  Thus the laser engraving depth is even more shallow so that it does not go through to the metal barrel.  If a pen or pencil is engraved and then you sand the barrel you may mistakenly remove the engraving.  You might also break off tiny segments of letters or logos.  Also, if you finish a pen after engraving you may fill the engraving with finish which often renders the engraving much less distinct and crisp.

 The best suggestion is to bring us or send us your turned wood pens and pencils already finished and assembled.