visual observation of any phase transitions until sedimentation appeared. Then some samples may be diluted with solvent while others were left opened for solvent to evaporate before re-homogenizing. In this way, a sequence of samples, some very close in composition, could be prepared.

Light scattering methods
------------------------

The slight difference in the refractive indices of PMMA and [*cis*]{}-decalin (1.49 and 1.48 respectively) was enough to render all of our samples turbid (transmission coefficients $\approx$ 20–40%). We therefore used two-color light scattering to extract the singly-scattered component. The detailed experimental arrangement and data analysis for this method have been described elsewhere [@two-colour]. Here we just summarize relevant procedures.

Two lasers of different wavelengths, blue ($\lambda_B=488$ nm) and green ($\lambda_G=514.5$ nm), and two detectors with filters were used in what were essentially two separate but simultaneous scattering experiments on the same scattering volume. The incident and scattered beams were arranged such that the scattering angles $\theta_B$ and $\theta_G$ were different but the scattering vectors were identical, i.e. ${{{\mathbf{q}}}}_B={{{\mathbf{q}}}}_G={{{\mathbf{q}}}}$, where $\left| {{{\mathbf{q}}}}\right|
=4n\pi\sin(\theta/2)/\lambda$ and $n$ is the refractive index of cis-decalin. The outputs of the two detectors were cross-correlated to give the intensity correlation function (ICF): $$\label{eq:ICF}
{g^{(2)}}(q,\tau)=\frac{\left<I_B(q,0)I_G(q,\tau)\right>}
{\left<I_B(q)\right> \left<I_G(q)\right>} \;,$$

where $I_B$ 