Tween 20 dilution

[ronlamarsh]

Just got a 30ml bottle of 100% tween 20. What is the most useful dilution? I plan on using it for alt process and as a photoflo substitute. Thanks

 

[Jerevan]

Look at http://www.mikeware.co.uk/mikeware/New_Cyanotype_Process.html under the header "Use of wetting agent" to get some idea. I have never had any reason to use so I can't say whether it is good or bad.

 

[Gerald C Koch]

For films you need just enough to break the surface tension of the water and prevent it from beading. Try 1 drop for 250 ml of water to start.

Kodak Photo-Flo uses a different chemical called Triton X-100. I mention it because it is not readily mscible with water and must be diluted with propylene glycol. Don't know about Tween 20 and it's miscibility. In the past X-100 was also sold as a solution in isopropyl alcohol for photo purposes.

 

[Mike Wilde]

I have used a drop of it (dip tip of eye dropper into tween bottle; don't squeeze bulb or you will spend forever trying the rinse it out of the insides of the dropper) ) into about 20mL of cyanotype solution. I mixed it in just prior to coating, when I am coating with a foam brush. I find it results in fewer bubbles.

So a little goes a long way.