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| Posted on 3/6/07 at 06:27 AM | |
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smacken3 writes: "No image appears after it is developed and spayed out." If by this description you mean that all of the emulsion comes off the mesh in the development sink, then it's likely that your exposure dosage is insufficient. This may be related to the amount of time you exposed the screen for, or it may have to do with a mismatch between the spectral wavelength output from your regular fluorescent lamp and the sensitivity needs of the QX1's photochemistry. Also, considering your bulb is 25 watts and Ulano's QX1 data sheet discusses a 40 watt lamp, it's possible that at 19" away the intensity of UV striking the exposure plane from your bulb may be a bit insufficient to initiate the crosslinking. However, if by your description you mean that the stencil is hardened and tolerant to the water development spray but the artwork pattern simply never appeared whatsoever, then check the density of your photopositive. Your exposure may be crosslinking the emulsion to sufficient hardness, but if UV is passing through the opaque areas of your photowork, those areas would be hardened as well. (Usually a densitomiter reading of 3.8 is sufficient to block UV). If you can see the latent image of the artwork after exposure but before water development, than as you speculated, you may need a longer development cycle. As someone suggested in a similar previous thread, contact Paul Drago at Ulano about this matter. He has intimate knowledge about QX1 and therefore would be in the best position to offer for good troubleshooting advice specific to this emulsion. Good luck. | ||
  
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