At the end of 1973, chisel-tipped overhead markers are added to the Lumocolor range.
The Lumocolor 305, another model with clip, and the Lumocolor F 306, equipped with a particularly fine tip, round off the assortment.

At this time, the technical drawing field is one of STAEDTLER's core competence areas. As a result, a lot of time and energy is invested in developing more innovative ideas for further expanding this product segment.

More writing instruments and accessories targeted at OHP users are developed in cooperation with experts from the education sector and film manufacturers.

In 1977 the Lumocolor cartridge pen with stainless steel drafting tube in three line widths - for a consistent line width and for use with lettering guides - and Lumoplast, a special eraser for erasing inks from overhead film are launched onto the market.

In the same year, the company is busy working on another new product, an OHP pen with superfine, metal-clad tip.

Lumocolor S 311 removable and S 313 permanent are ready for market launch in November 1977.

These models hardly differ from contemporary products in shape, size and design.

All Lumocolor writing instruments are available individually or in sets of 4, 6, or 8 pens. Special sets comprising pens, erasers and compasses with fibre-tip pen adapters round of the Lumocolor range.

STAEDTLER continues to work on developing the product still further, taking increased demand and new requirements and applications into account.  Once again, in 1977, it is STAEDTLER which is the first company to bring out an OHP pen in line width F (0.6 mm) followed, one year later, by line width S (0.4 mm).