Virtually any wood used to create a turned pen can be engraved.  We have also engraved pens made from man-made materials such as acrylics and laminates.  We could also mark (engrave a material onto a surface) metal pens that DO NOT have any finish (lacquer or other) coating.

Lighter tightly grained woods result in better contrast with the laser engraving.  Excellent examples are olive wood, maple, birch, butternut, pecan, holly and similar woods.  Lighter open  grain woods that do not engrave as well include oak and ash.  They engrave find, but the growth rings and other heavy pitch areas engrave become darker while the other areas hardly change color at all.  Oak and ash can be laser engraved, but it takes more time and might cost a bit extra.

Dark woods, while they engrave fine with the laser, do not show up as well because of the limited contrast between the wood and the engraving.  This can be solved or mitigated by filling the engraving with a lighter, better contrasting material.

Alternating light and dark woods such as zebrawood and goncalo alves sometimes work well and sometimes are not so good.  The judgement will depend on where the color changes are on the barrell in relation to the engraving. 

Burl woods such as walnut burl can end up with tiny voids just beneath the surface that may be exposed when engraved.  Sometimes these 'broken out' areas can be touched up with a black pen or other paint-type application.  In some cases the void may drastically impact the result such that the pen is considered unusable.  We can't be liable for voids found in the wood, but we will always do our best to work with you and suggest solutions.