There are different types of OHP transparencies:

• Smooth finish on both sides: meant for simple writing or drawing –  smearing or marker pen
• Textured surface on one side: different types for inkjet, laser and screenprinting. These give a more varied line and/or hold ink better on the textured side.

Overhead Projector Transparency slides were a Happy Accident discovery in a number of ways, first in Part 4 Experimental Book: Anon, then in Assignment 5: Letter O .

Layering to intensify colours and/or juxtapositions

My original intention in experimenting with OHP transparencies was to see if they intensified the colours either in themselves and/or when overlaid on top of paper copies of the same images. In general this was the case. But I also found that reversing the transparency image and/or putting it on top of another image could lead to very interesting juxtapositions and/or new ideas for the image that could then be further scanned and reprinted.

Praying overlay

Strange people – or cityscapes depending on which way up.

Into the Vortex overlay

reverse overlay

Printing on the ‘wrong side’

My first ‘accident’ was that I could not remember which side to print on, and automatically assumed it would be the smooth side. This produced some really interesting blurry puddled images as the ink did not dry immediately, but moved around on the slide.

Sheep

water

steps

Palace

Mechanical Head

Accidental smears

The second related accident was that I did not realise the ink was not dry and many of the images were placed on top of each other. This led to smearing on either the slide and/or the image on which it was placed. In some cases this led to very interesting textures and/or juxtapositions.

Praying smear

Swimming

accidental print

As I played around with the images, some invariably became scratched. This produced some interesting ‘distressed effects’. It also opens the possibility for scratch drawing.

Xmas distressed

Working on both sides and overlaying

This is a further possibility that can yield atmospheric effects. Media like oil pastel can be made grainy or smeared. In ‘Letter O’ this was not so successful in smearing. But these techniques can be further developed. Either drawing on both sides, laying one OHP on top of the other and/or digital compositing.

If the slides are slightly separated then it is possible to get a 3D effect and create depth.