PRESERVATION OF SPECIMENS IN PLASTICS 29 



CARE OF FINISHED MOUNTS 



Natural-color preserved specimens mounted between sheets of 

 Vinylite plastic have been found to be generally resistant to deteriora- 

 tion under normal conditions of use and storage. To obtain the best 

 results, however, it is advisable to observe the following precautions in 

 handling them. 



Moisture. — These mounts can be safely washed with water and ex- 

 posed to extremely humid conditions for moderately long periods. 

 Prolonged or continuous exposure, however, to relative humidities of 

 over 85 percent is not recommended, and where such conditions do 

 prevail, it is advisable to store the mounts in a box or cabinet contain- 

 ing a desiccant. 



Temperature . — Temperatures up to 45° C. (113° F.) do not have 

 any apparent effect upon these mounts other than to produce a slight 

 softening of the cementing resin around the edges. In general, how- 

 ever, it is advisable to avoid prolonged exposures to temperatures above 

 40° C: (104° F.). 



Light. — Tests indicate that the colors in specimens that have been 

 properly preserved and mounted in a moisture-free state are stable 

 indefinitely, provided they are not exposed to direct sunlight. 



Cleaning. — If these mounts become soiled they should be cleaned with 

 soapy water and then rinsed with clear water. Distilled water is pref- 

 erable for rinsing because it leaves no residue on drying. Either cold or 

 slightly warm water may be used, but never water hotter than 50° C. 

 (122° F.). AVater-insoluble material adhering to the surface should be 

 removed either with ethyl alcohol or mineral spirits or an 80/20 mixture 

 of these solvents. It is not advisable to use any other organic solvents 

 on Vinylite plastic; and ketones, esters, ethers, aromatic hydrocarbons, 

 and chlorinated solvents should in particular be avoided. 



Refinishing. — Unless reasonable care is exercised in handling the 

 mounts, abrasions or scratches may in time mar the surface of the plas- 

 tic. Slight scratches can usually be removed by careful polishing with 

 tripoli polish (or with other suitable polishing compounds) on a buffing 

 wheel. Polishing with magnesium carbonate on wet felt is also helpful 

 in restoring the luster on surfaces that have become dull. All polishing 

 of Vinylite plastic should be done at moderate speeds and with only very 

 light pressure on the buffing wheel in order to avoid damaging the sur- 

 face of the plastic through overheating. 



Storage and shipping. — While no special precautions are necessary in 

 storing or shipping these mounts, it is best to avoid subjecting them 

 to excessive heat and moisture for prolonged periods. Since these 

 mounts are practically no more inflammable than ordinary paper they 

 may be considered as not constituting a fire hazard and can, therefore, 

 be handled or shipped without restrictions. Special safeguards against 

 breakage during shipment are not necessary, but when packing them 

 it is advisable to- wrap them individually with cellulose film or with 

 tissue paper or soft fabric as a precaution against abrasions or scratches. 



