SketchChair Valchromat Material Test

DIO Children's Chair Prototype


This is a 2:3 scale SketchChair prototype version of the DIO design, previously tested as a 1:4 scale cardboard miniature in this project from november:  Cardboard SketchChair Miniatures.   The purpose of this prototype was to test a material sample of Valchromat, from the portuguese company Investwood.  Valchromat is an mdf-like fiber board that is coloured with textile dyes.


For more info on SketchChair please see


This is a project by London based design studio, Diatom Studio.







The material samples were two 600x800 sheets of 8.4mm, so the full scale pattern for 12mm material was scaled to about 61% to create slots of the correct size and to fit on the sheets.  The resulting chair was about 2/3 scale, making it about the right size for a small child.


These cuts were made in about 5 or 6 passes, and overall the chair took about 2 hours to cut.  The material cut very easily though, and could probably be cut much more quickly.














The cnc cutting pattern for “DIO”



Saw, Sandpaper and File


The parts where very easy to clean up compared to MDF.  Valchromat seems to have a texture a bit like cardboard, and does not produce dust that is as fine and irritating as MDF.


There was a mistake in the dimensions of the fingerjoints – they included the overlap from the lasercutting pattern that allows for the kerf of the laser, and so this overlap had to be cut down manuallly afterwards.  Aside from this the fit was good and hardly any sanding was need to get the parts to fit together.  (this has been fixed in the attached pdf, v2)


Despite being only 8mm, the valchromat seems to work very well mechanically.  The chair might not easily support an adult but seems very suitable for a child and holds together well.  The material is slightly elastic and holds a lot of tension in the joints.


Diagrams to help with assembling the DIO design will be available in the design library at some point.

The initial cut on the machine

Manually resizing the finger-joints

Assembled at AltLab,

dio_v2_8.4mm.pdf365.13 KB

Tiago Rorke's picture
Last updated: 09/02/2015